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LM3535
SNVS598B – AUGUST 2010 – REVISED MARCH 2018
LM3535 Multi-Display LED Driver With Ambient Light Sensing and Dynamic
Backlight Control Compatibility
1 Features
3 Description
•
The LM3535 device is a highly integrated LED driver
capable of driving 8 LEDs in parallel for large display
applications. Independent LED control allows
selection of a subset of the 6 main display LEDs for
partial-illumination applications. In addition to the
main bank of 6, the LM3535 is capable of driving an
additional 2 independently controlled LEDs to support
Indicator applications.
1
•
•
•
•
•
•
•
•
•
•
•
•
•
Drives Up to 8 LEDs Each With Up to 25 mA of
Diode Current
External PWM Input for Dynamic Backlight Control
Multi-Zone Ambient Light Sensing (ALS)
ALS Interrupt Reporting
Independent On/Off Control for All Current Sinks
128 Exponential Dimming Steps With 600:1
Dimming Ratio for Group A (Up to 6 LEDs)
8 Linear Dimming States for Groups B (Up to 3
LEDs) and D1C (1 LED)
Programmable Auto-Dimming Function
Up to 90% Efficiency
0.55% Accurate Current Matching
Wide Input Voltage Range (2.7 V to 5.5 V)
Active High Hardware Enable
Total Solution Size < 16 mm2
Low Profile 20-Pin DSBGA Package
The LED driver current sinks are split into three
independently controlled groups. The primary group
can be configured to drive up to six LEDs for use in
the main phone display. Groups B and C are
provided for driving secondary displays, keypads and
indicator LEDs. All of the LED current sources can be
independently turned on and off providing flexibility to
address different application requirements.
The LM3535 provides multi-zone ambient light
sensing allowing autonomous backlight intensity
control in the event of changing ambient light
conditions. A PWM input is also provided to give the
user the means to adjust the backlight intensity
dynamically based upon the content of the display.
2 Applications
•
•
•
The LM3535 provides excellent efficiency without the
use of an inductor by operating the charge pump in a
gain of 3/2 or in pass mode. The proper gain for
maintaining current regulation is chosen, based on
LED forward voltage, so that efficiency is maximized
over the input voltage range.
Smart-Phone LED Backlighting
Large Format LCD Backlighting
General LED Lighting
The LM3535 is available in a tiny 20-pin, 0.4-mm
pitch, thin DSBGA package.
Device Information(1)
PART NUMBER
LM3535
PACKAGE
DSBGA (20)
BODY SIZE (MAX)
2.045 mm × 1.64 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Typical Application
GROUP A
GROUP B
GROUP C
VIO
O
R
D1A D2A D3A D4A
D53
D62
VIN
+ -
1µF
D1B/ D1C/
INT ALS
VOUT
C1+
1µF
C1C2+
1µF
C2-
LM3535
1µF
GND
HWEN SDIO SCL PWM
I 2C
Control
Signals
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
LM3535
SNVS598B – AUGUST 2010 – REVISED MARCH 2018
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Table of Contents
1
2
3
4
5
6
7
Features ..................................................................
Applications ...........................................................
Description .............................................................
Revision History.....................................................
Pin Configuration and Functions .........................
Specifications.........................................................
1
1
1
2
3
4
6.1
6.2
6.3
6.4
6.5
6.6
4
4
4
5
5
7
Absolute Maximum Ratings ......................................
ESD Ratings..............................................................
Recommended Operating Conditions.......................
Thermal Information ..................................................
Electrical Characteristics...........................................
Typical Characteristics ..............................................
Detailed Description ............................................ 10
7.1 Overview ................................................................. 10
7.2 Functional Block Diagram ....................................... 10
7.3 Feature Description................................................. 11
7.4 Device Functional Modes........................................ 12
7.5 Programming........................................................... 12
8
Application and Implementation ........................ 19
8.1 Application Information............................................ 19
8.2 Typical Application ................................................. 19
9 Power Supply Recommendations...................... 28
10 Layout................................................................... 29
10.1 Layout Guidelines ................................................. 29
10.2 Layout Example .................................................... 29
11 Device and Documentation Support ................. 30
11.1
11.2
11.3
11.4
11.5
Receiving Notification of Documentation Updates
Community Resources..........................................
Trademarks ...........................................................
Electrostatic Discharge Caution ............................
Glossary ................................................................
30
30
30
30
30
12 Mechanical, Packaging, and Orderable
Information ........................................................... 30
4 Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
Changes from Revision A (May 2013) to Revision B
Page
•
Added Pin Configuration and Functions section, ESD Ratings table, Feature Description, Device Functional Modes,
Application and Implementation, Power Supply Recommendations , Layout , Device and Documentation Support ,
and Mechanical, Packaging, and Orderable Information ....................................................................................................... 1
•
Deleted references to "ALS2" option ..................................................................................................................................... 1
•
Changed ALS resistor accuracy values from –5% and 5% to –9% and 9% ......................................................................... 6
Changes from Original (May 2013) to Revision A
•
2
Page
Changed layout of National Data Sheet to TI format ........................................................................................................... 27
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SNVS598B – AUGUST 2010 – REVISED MARCH 2018
5 Pin Configuration and Functions
YFQ Package
20-Pin DSBGA
Top View
4
4
3
3
2
2
1
1
A
B
C
D
E
E
Top View
D
C
B
A
Bottom View
Pin Functions
PIN
NO.
A1, C1, B1, B2
NAME
DESCRIPTION
TYPE
C1+, C1–, C2+,
C2–
Power
VOUT
Power
Charge pump output voltage
A3
VIN
Power
Input voltage; input range: 2.7 V to 5.5 V
A4
GND
Power
Ground
B3
D1B / INT
Input /
Output
LED driver/ ALS interrupt - GroupB current sink or ALS interrupt pin. In ALS Interrupt
mode, a pullup resistor is required. A zero (0) means a change has occurred, while
a one (1) means no ALS adjustment has been made.
B4, C4
A2
Flying capacitor connections
D53, D62
Output
LED drivers - configurable current sinks. Can be assigned to GroupA or GroupB
C2
SDIO
Input /
Output
Serial data input/output pin
C3
D1C / ALS
Input /
Output
LED driver / ALS input - indicator LED current sink or ambient light sensor input
D1
GND
Power
Ground
D2
PWM
D3, E3, E4, D4
Input
External PWM input - allows the current sinks to be turned on and off at a frequency
and duty cycle externally controlled. Minimum on-time pulse width = 15 µsec.
D1A-D4A
Output
E1
HWEN
Input
LED drivers - GroupA
Hardware enable pin. High = normal operation, Low = RESET
E2
SCL
Input
Serial clock pin
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6 Specifications
6.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted) (1) (2) (3)
MIN
MAX
UNIT
VIN pin voltage
–0.3
6
V
SCL, SDIO, HWEN, PWM pin voltages
–0.3
(VIN + 0.3 V) with 6 V
maximum
V
IDxx pin voltages
–0.3
(VVOUT + 0.3 V) with 6 V
maximum
V
Continuous power dissipation (4)
Internally limited
Junction temperature, tJ-MAX
150
Storage temperature, Tstg
(1)
(2)
(3)
(4)
(5)
°C
See (5)
Maximum lead temperature (soldering)
–65
°C
150
°C
Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended
Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
All voltages are with respect to the potential at the GND pins.
If Military/Aerospace specified devices are required, contact the Texas Instruments Sales Office/ Distributors for availability and
specifications. All voltages are with respect to the potential at the GND pins.
Internal thermal shutdown circuitry protects the device from permanent damage. Thermal shutdown engages at TJ = 150°C (typical) and
disengages at TJ = 125°C (typical).
For detailed soldering specifications and information, see Texas Instruments Application Report AN-1112 DSBGA Wafer Level Chip
Scale Package.
6.2 ESD Ratings
V(ESD)
(1)
(2)
Electrostatic discharge
Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001
(1) (2)
VALUE
UNIT
±2000
V
JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
The human body model is a 100-pF capacitor discharged through a 1.5-kΩ resistor into each pin. (MIL-STD-883 3015.7).
6.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted) (1) (2)
MIN
MAX
Input voltage
2.7
5.5
LED voltage
2
4
V
Junction temperature, TJ
–30
110
°C
Ambient temperature, TA (3)
–30
85
°C
(1)
(2)
(3)
4
UNIT
V
Absolute Maximum Ratings indicate limits beyond which damage to the component may occur. Recommended Operating Ratings are
conditions under which operation of the device is ensured. Recommended Operating Ratings do not imply ensured performance limits.
For ensured performance limits and associated test conditions, see the Electrical Characteristics tables.
All voltages are with respect to the potential at the GND pins.
In applications where high power dissipation and/or poor package thermal resistance is present, the maximum ambient temperature may
have to be derated. Maximum ambient temperature (TA-MAX) is dependent on the maximum operating junction temperature (TJ-MAX-OP =
110°C), the maximum power dissipation of the device in the application (PD-MAX), and the junction-to ambient thermal resistance of the
device/package in the application (RθJA), as given by the following equation: TA-MAX = TJ-MAX-OP – (RθJA × PD-MAX).
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6.4 Thermal Information
LM3535
THERMAL METRIC (1)
YFQ (WCSP)
UNIT
20 PINS
RθJA
Junction-to-ambient thermal resistance
70.5
°C/W
RθJC(top)
RθJB
Junction-to-case (top) thermal resistance
0.6
°C/W
Junction-to-board thermal resistance
16.7
°C/W
ψJT
Junction-to-top characterization parameter
0.4
°C/W
ψJB
Junction-to-board characterization parameter
16.9
°C/W
RθJC(bot)
Junction-to-case (bottom) thermal resistance
N/A
°C/W
(1)
For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application
report.
6.5 Electrical Characteristics
Typical limits are TA = 25°C, and minimum and maximum limits in apply over the full operating temperature range (–30°C to
+85°C). Unless otherwise specified: VIN = 3.6 V; VHWEN = VIN; VPWM = 0 V; VDxA = VDxB = VDxC = 0.4 V; GroupA = GroupB =
GroupC = full-scale current; ENxA, ENxB, ENxC bits = 1; 53A, 62A bits = 0; C1 = C2 = CIN = COUT= 1 µF. (1) (2) (3)
PARAMETER
MIN
TYP
MAX
2.7 V ≤ VIN ≤ 5.5 V
EN1A to EN4A = 1, 53A = 62A = 0, EN53
= EN62 = ENxB = ENxC = 0
4 LEDs in GroupA
23.6
(–5.6%)
25
26.3
(5.2%)
mA
(%)
2.7 V ≤ VIN ≤ 5.5 V
EN1A to EN4A = EN53 = EN62 = 1, 53A =
62A = 1, ENxB = ENxC = 0
6 LEDs in GroupA
23.2
(–7.2%)
25
26.3
5.2%
mA
(%)
Output current regulation
GroupB
2.7 V ≤ VIN ≤ 5.5 V
EN1B = EN53 = EN62 = 1, 53A = 62A = 0,
ENxA = ENC = 0
3 LEDs in GroupB
23.3
(–6.8%)
25
(+4%)
mA
(%)
Output current regulation
IDC
2.7 V ≤ VIN ≤ 5.5 V
ENC = 1, ENxA = ENxB = 0
23.8
(–4.8%)
25
26.8
(7.2%)
mA
(%)
Output current regulation
GroupA
IDxx
TEST CONDITIONS
UNIT
25
DxA
Output current regulation
GroupA, GroupB, and GroupC
enabled
3.2 V ≤ VIN ≤ 5.5V
VLED = 3.6 V
25
DxB
mA
25
DxC
IDxx-
LED current matching (4)
MATCH
2.7 V ≤ VIN ≤ 5.5 V
GroupA (4
LEDs)
0.25%
2.4%
GroupA (6
LEDs)
0.55%
2.78
GroupB (3
LEDs)
0.25%
2.41%
VDxTH
VDxx 1x to 3/2x gain transition
threshold
VDxA and/or VDxB falling
130
mV
VHR
Current sink headroom voltage
requirement (5)
IDxx = 95% ×IDxx (nominal)
(IDxx (nominal) = 25 mA)
100
mV
(1)
(2)
(3)
(4)
(5)
All voltages are with respect to the potential at the GND pins.
Minimum and maximum limits are ensured by design, test, or statistical analysis. Typical numbers are not ensured, but do represent the
most likely norm.
CIN, CVOUT, C1, and C2 : Low-ESR surface-mount ceramic capacitors (MLCCs) used in setting electrical characteristics
For the two groups of current sinks on a part (GroupA and GroupB), the following are determined: the maximum sink current in the
group (MAX), the minimum sink current in the group (MIN), and the average sink current of the group (AVG). For each group, two
matching numbers are calculated: (MAX-AVG)/AVG and (AVG-MIN)/AVG. The largest number of the two (worst case) is considered the
matching figure for the Group. The matching figure for a given part is considered to be the highest matching figure of the two Groups.
The typical specification provided is the most likely norm of the matching figure for all parts.
For each Dxxpin, headroom voltage is the voltage across the internal current sink connected to that pin. For Group A, B, and C current
sinks, VHRx = VOUT – VLED. If headroom voltage requirement is not met, LED current regulation will be compromised.
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Electrical Characteristics (continued)
Typical limits are TA = 25°C, and minimum and maximum limits in apply over the full operating temperature range (–30°C to
+85°C). Unless otherwise specified: VIN = 3.6 V; VHWEN = VIN; VPWM = 0 V; VDxA = VDxB = VDxC = 0.4 V; GroupA = GroupB =
GroupC = full-scale current; ENxA, ENxB, ENxC bits = 1; 53A, 62A bits = 0; C1 = C2 = CIN = COUT= 1 µF.(1)(2)(3)
PARAMETER
ROUT
Open-loop charge pump output
resistance
IQ
Quiescent supply current
ISB
Standby supply current
ISD
Shutdown supply current
fSW
Switching frequency
tSTART
Start-up time
VALS
ALS reference voltage accuracy
RALS
ALS resistor accuracy
TEST CONDITIONS
VPWM
VOL-INT
TYP
2.4
Gain = 1
0.5
MAX
Ω
2.86
4.38
Gain = 1, no load
1.09
2.31
2.7 V ≤ VIN ≤ 5.5 V
HWEN = VIN, all ENx bits = 0
1.7
4
µA
2.7 V ≤ VIN ≤ 5.5 V
HWEN = 0 V, All ENx bits = 0
1.7
4
µA
1.33
1.56
1.1
VOUT = 90% steady state
250
0.95
(–5%)
1
RALS = 9.08 kΩ
–9%
RALS = 5.46 kΩ
–9%
9%
0
0.45
MHz
1.2
VIN
V
9%
2.7 V ≤ VIN ≤ 5.5 V
Normal
operation
PWM voltage thresholds
2.7 V ≤ VIN ≤ 5.5 V
Diodes off
0
0.45
Diodes on
1.2
VIN
ILOAD = 3 mA
mA
µs
1.05
5%
HWEN voltage thresholds
Interrupt output logic low 0
UNIT
Gain = 3/2, no load
Reset
VHWEN
MIN
Gain = 3/2
V
V
400
mV
0.45
V
I2C-COMPATIBLE INTERFACE VOLTAGE SPECIFICATIONS (SCL, SDIO)
VIL
Input logic low 0
2.7 V ≤ VIN ≤ 5.5 V
0
VIH
Input logic high 1
2.7 V ≤ VIN ≤ 5.5 V
1.2
VOL
SDIO output logic low 0
ILOAD = 3 mA
VIN
V
400
mV
I2C-COMPATIBLE INTERFACE TIMING SPECIFICATIONS (SCL, SDIO)
t1
SCL (clock period)
t2
Data in setup time to SCL high
t3
Data out stable after SCL low
See (6)
2.5
µs
100
ns
0
ns
t4
SDIO low setup time to SCL low
(start)
100
ns
t5
SDIO high hold time after SCL high
(stop)
100
ns
(6)
SCL is tested with a 50% duty-cycle clock.
Figure 1. I2C Timing Diagram
6
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6.6 Typical Characteristics
Unless otherwise specified: TA = 25°C; VIN = 3.6 V; VHWEN = VIN; CIN= 1 µF, COUT = 1 µF, C1 = C2 = 1 µF.
27.5
27.5
27.0
27.0
26.5
26.5
26.0
IDx (mA)
IDx (mA)
26.0
D62
D1A,D2A,D3A,D53
25.5
25.0
24.5
D4A
24.0
TA = +85°C
25.5
25.0
24.5
TA = -30°C
24.0
TA = +25°C
23.5
23.5
BRC = 127
23.0
22.5
2.7
3.1
3.5
3.9
4.3
4.7
5.1
BRC = 127
23.0
22.5
2.7
5.5
3.1
3.5
3.9 4.3
VIN (V)
VIN (V)
4.7
5.1
5.5
Figure 3. ILED vs Input Voltage
Figure 2. ILED vs Input Voltage 6 LEDs
30
1.00e2
TA = -30°C,+25°C and +85°C
TA = -30°C,+25°C and +85°C
25
1.00e1
IDX (mA)
IDX (mA)
20
15
1.00
10
1.00e-1
5
0
0
16
32
48
64
80
96
1.00e-2
0
112 128
16
32
48
BRC (#)
64
80
96
112 128
BRC (#)
Figure 4. ILED vs Brightness Code Linear Scale
Figure 5. ILED vs Brightness Code Log Scale
1.6
4.00
VSCL = VSDIO = 0V
3.50
1.5
TA = -30°C
3.00
2.50
ISD (PA)
fSW (MHz)
1.4
1.3
TA = +25°C
1.2
1.50
1.00
TA = +85°C
1.1
1.0
2.7
TA = +85°C
2.00
TA = -30°C, +25°C
0.50
3.1
3.5
3.9
4.3
4.7
5.1
0.00
2.7
5.5
VIN (V)
3.1
3.5
3.9
4.3
4.7
5.1
5.5
VIN (V)
Figure 6. Switching Frequency vs Input Voltage Tri-Temp
Figure 7. Shutdown Current vs Input Voltage VIO = 0 V
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Typical Characteristics (continued)
Unless otherwise specified: TA = 25°C; VIN = 3.6 V; VHWEN = VIN; CIN= 1 µF, COUT = 1 µF, C1 = C2 = 1 µF.
10.00
2.00
VSCL = VSDIO = 2.5V
9.00
1.75
8.00
7.00
1.50
TA = +85°C
6.00
IQ-1x (mA)
ISD (PA)
TA = -30°C
TA = +25°C
TA = -30°C
5.00
4.00
1.25
1.00
0.75
TA = +85°C
3.00
0.50
TA = +25°C
2.00
0.25
1.00
0.00
2.7
3.1
3.5
3.9
4.3
4.7
5.1
0.00
2.7
5.5
3.1
3.5
VIN (V)
3.9
4.3
4.7
5.1
5.5
VIN (V)
Figure 8. Shutdown Current vs Input Voltage VIO = 2.5 V
Figure 9. Quiescent Current vs Input Voltage 1× Gain
4.0
3.5
3.0
IQ-3/2x (mA)
TA = -30°C
2.5
2.0
1.5
TA = +85°C
TA = +25°C
1.0
0.5
0.0
2.7
3.1
3.5
3.9
4.3
4.7
5.1
5.5
VIN (V)
Figure 10. Quiescent Current vs Input Voltage 3/2× Gain
Figure 11. ALS Boundary Voltage vs Boundary Code Falling
ALS Voltage
25
fPWM = 250 Hz.
20
ILEDx (mA)
fPWM = 8 kHz.
15
10
fPWM = 20 kHz.
5
0
0
20
40
60
80
100
D.C. (%)
Figure 12. ALS Boundary Voltage vs Boundary Code Falling
ALS Voltage (Zoom)
8
Figure 13. Diode Current vs PWM Duty Cycle
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Typical Characteristics (continued)
Unless otherwise specified: TA = 25°C; VIN = 3.6 V; VHWEN = VIN; CIN= 1 µF, COUT = 1 µF, C1 = C2 = 1 µF.
INT
VOUT
1V/div.
VALS
200 mV/div.
ILEDs
ILEDs
(20 mA/div.)
(50 mA/div.)
Time
(100 ms/div.)
Time
(100 ms/div.)
Figure 14. Ambient Light Sensor Response
Figure 15. Diode Current Ramp-Up TSTEP = 6 ms
VOUT
1V/div.
ILEDs
(20 mA/div.)
Time
(100 ms/div.)
Figure 16. Diode Current Ramp-Down TSTEP = 6 ms
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7 Detailed Description
7.1 Overview
The LM3535 is a white LED driver system based upon an adaptive 3/2× – 1× CMOS charge pump capable of
supplying up to 200 mA of total output current. With three separately controlled groups of constant current sinks,
the LM3535 is an ideal solution for platforms requiring a single white LED driver IC for main display, sub display,
and indicator lighting. The tightly matched current sinks ensure uniform brightness from the LEDs across the
entire small-format display.
Each LED is configured in a common anode configuration, with the peak drive current set to 25 mA. An I2C
compatible interface is used to enable the device and vary the brightness within the individual current sink
Groups. For GroupA, 128 exponentially-spaced analog brightness control levels are available. GroupB and
GroupC have 8 linearly-spaced analog brightness levels.
Additionally, the LM3535 provides 1 inputfor an ambient light sensor to adaptively adjust the diode current based
on ambient conditions, and a PWM pin to allow the diode current to be pulse width modulated to work with a
display driver utilizing dynamic or content adjusted backlight control (DBC or CABC).
7.2 Functional Block Diagram
VIO
1 PF
COUT
1 PF
1 PF
OR
C1+
C1-
C2+
VOUT
C2-
D1A
D2A
D3A
D4A
D53
D62
D1B/INT
D1C/ALS
VIN
2.7V to 5.5V
3/2X and 1X
Regulated Charge Pump
CIN
1 PF
GroupB
Current
Sinks
GroupA Current Sinks
GAIN
CONTROL
INT
D1C Current
Sink
ALS
PWM
1.3 MHz.
Switch
Frequency
Soft
Start
Brightness
Control
Brightness
Control
Brightness
Control
General Purpose Register
SCL
SDIO
1.25 V
Ref.
I2C Interface
Block
Brightness Control Registers
Group A and Group B
HWEN
Brightness Control Register
D1C
LM3535
RSET
GND
10
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7.3 Feature Description
7.3.1 Charge Pump
The input to the 3/2× or 1× charge pump is connected to the VIN pin, and the regulated output of the charge
pump is connected to the VOUT pin. The recommended input voltage range of the LM3535 is 2.7 V to 5.5 V. The
device regulated charge pump has both open loop and closed loop modes of operation. When the device is in
open loop, the voltage at VOUT is equal to the gain times the voltage at the input. When the device is in closed
loop, the voltage at VOUT is regulated to 4.3 V (typical). The charge pump gain transitions are actively selected to
maintain regulation based on LED forward voltage and load requirements.
7.3.2 Diode Current Sinks
Matched currents are ensured with the use of tightly matched internal devices and internal mismatch cancellation
circuitry. There are eight regulated current sinks configurable into 3 different lighting regions.
7.3.3 Ambient Light Sensing (ALS) And Interrupt
The LM3535 provides an ambient light sensing input for use with ambient backlight control. By connecting the
anode of a photo diode / sensor to the sensor input pins, and configuring the appropriate ALS resistors, the
LM3535 can be configured to adjust the diode current to five unique settings, corresponding to four adjustable
light region trip points. Additionally, when the LM3535 determines that an ambient condition has changed, the
interrupt pin, when connected to a pullup resistor toggles to a 0 alerting the controller. See I2C Compatible
Interface for more details regarding the register configurations.
7.3.4 Dynamic Backlight Control Input (PWM Pin)
The pulse width modulation (PWM) pin allows a display driver utilizing dynamic backlight control (DBC) to adjust
the LED brightness based on the content. The PWM input can be turned on or off (Acknowledge or Ignore), and
the polarity can be flipped (active high or active low) through the I2C interface. The current sinks of the LM3535
require approximately 15 µs to reach steady-state target current. This turnon time sets the minimum usable PWM
pulse width for DBC/CABC.
7.3.5 LED Forward Voltage Monitoring
The LM3535 has the ability to switch gains (1× or 3/2×) based on the forward voltage of the LED load. This
ability to switch gains maximizes efficiency for a given load. Forward voltage monitoring occurs on all diode pins.
At higher input voltages, the LM3535 operates in pass mode, allowing the VOUT voltage to track the input voltage.
As the input voltage drops, the voltage on the Dxx pins also drops (VDXX = VVOUT – VLEDx). Once any of the active
Dxx pins reaches a voltage approximately equal to 130 mV, the charge pump will switch to the gain of 3/2. This
switchover ensures that the current through the LEDs never becomes pinched off due to a lack of headroom
across the current sinks. Once a gain transition occurs, the LM3535 remains in the gain of 3/2 until an I2C write
to the part occurs. At that time, the LM3535 re-evaluates the LED conditions and selects the appropriate gain.
Only active Dxx pins are monitored.
7.3.6 Configurable Gain Transition Delay
To optimize efficiency, the LM3535 has a user selectable gain transition delay that allows the part to ignore short
duration input voltage drops. By default, the LM3535 does not change gains if the input voltage dip is shorter
than 3 to 6 milliseconds. There are three selectable gain transition delay ranges available on the LM3535. All
delay ranges are set within the VF Monitor Delay Register. See Internal Registers of LM3535 for more
information regarding the delay ranges.
7.3.7 Hardware Enable (HWEN)
The LM3535 has a hardware enable/reset pin (HWEN) that allows the device to be disabled by an external
controller without requiring an I2C write command. Under normal operation, hold the HWEN pin high (logic 1) to
prevent an unwanted reset. When the HWEN is driven low (logic 0), all internal control registers reset to the
default states, and the device becomes disabled. See the Electrical Characteristics section of the data sheet for
required voltage thresholds.
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7.4 Device Functional Modes
7.4.1 Shutdown
The LM3535 enters shutdown mode if HWEN pin is held low. In this mode, the LM3535 has a shutdown current
of 1.7 µA. I2C communication is not possible when in shutdown.
7.4.2 Standby
The LM3535 enters standby mode if HWEN pin is held high and when the ENx bits are set to 0. In this mode, the
LM3535 has a standby current of 1.7 µA. I2C communication is possible when in standby.
7.4.3 Active Mode
The LM3535 enters active mode if HWEN pin is held high and when any of the ENx bits are set to 1. When the
LM3535 is in pass-mode operation, the typical quiescent current drawn is 1.09 mA. When the LM3535 is in
boost-mode operation, the typical quiescent current drawn is 2.86 mA. I2C communication is possible when in
active mode.
7.5 Programming
7.5.1 I2C Compatible Interface
7.5.1.1 Data Validity
The data on SDIO line must be stable during the HIGH period of the clock signal (SCL). In other words, state of
the data line can only be changed when SCL is LOW.
SCL
SDIO
data
change
allowed
data
valid
data
change
allowed
data
valid
data
change
allowed
Figure 17. Data Validity Diagram
A pullup resistor between the VIO line and SDIO of the controller must be greater than [(VIO – VOL) / 3 mA] to
meet the VOL requirement on SDIO. Using a larger pullup resistor results in lower switching current with slower
edges, while using a smaller pullup results in higher switching currents with faster edges.
7.5.1.2 Start and Stop Conditions
START and STOP conditions classify the beginning and the end of the I2C session. A START condition is
defined as SDIO signal transitioning from HIGH to LOW while SCL line is HIGH. A STOP condition is defined as
the SDIO transitioning from LOW to HIGH while SCL is HIGH. The I2C master always generates START and
STOP conditions. The I2C bus is considered to be busy after a START condition and free after a STOP condition.
During data transmission, the I2C master can generate repeated START conditions. First START and repeated
START conditions are equivalent, function-wise.
SDIO
SCL
S
P
START condition
STOP condition
Figure 18. Start and Stop Conditions
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Programming (continued)
7.5.1.3 Transferring Data
Every byte put on the SDIO line must be eight bits long, with the most significant bit (MSB) transferred first. Each
byte of data has to be followed by an acknowledge bit. The acknowledge related clock pulse is generated by the
master. The master releases the SDIO line (HIGH) during the acknowledge clock pulse. The LM3535 pulls down
the SDIO line during the 9th clock pulse, signifying an acknowledge. The LM3535 generates an acknowledge
after each byte is received. There is no acknowledge created after data is read from the LM3535.
After the START condition, the I2C master sends a chip address. This address is seven bits long followed by an
eighth bit which is a data direction bit (R/W). The LM3535 7-bit address is 38h. For the eighth bit, a “0” indicates
a WRITE and a “1” indicates a READ. The second byte selects the register to which the data will be written. The
third byte contains data to write to the selected register.
ack from slave
ack from slave
ack from slave
start
msb Chip Address lsb
w
ack
msb Register Add lsb
ack
msb
DATA
lsb
ack
stop
start
Id = 38h
w
ack
addr = 10h
ack
DGGUHVV K¶3F data
ack
stop
SCL
SDIO
Figure 19. Write Cycle
W = Write (SDIO = 0)
R = Read (SDIO = 1)
Ack = Acknowledge (SDIO Pulled Down by Either Master or Slave)
Id = Chip Address, 38h For Lm3535
7.5.1.4 I2C Compatible Chip Address
The 7-bit chip address for LM3535 is 111000, or 0x38.
7.5.1.5 Internal Registers of LM3535
REGISTER
INTERNAL HEX ADDRESS
POWER ON VALUE
Diode Enable Register
0x10
0000 0000 (0x00)
Configuration Register
0x20
0000 0000 (0x00)
Options Register
0x30
0000 0000 (0x00)
ALS Zone Readback
0x40
1111 0000 (0xF0)
ALS Control Register
0x50
0000 0011 (0x03)
ALS Resistor Register
0x51
0000 0000 (0x00)
ALS Zone Boundary #0
0x60
0011 0011 (0x33)
ALS Zone Boundary #1
0x61
0110 0110 (0x66)
ALS Zone Boundary #2
0x62
1001 1001 (0x99)
ALS Zone Boundary #3
0x63
1100 1100 (0xCC)
ALS Brightness Zone #1
0x70
1001 1001 (0x99)
ALS Brightness Zone #2
0x71
1011 0110 (0xB6)
ALS Brightness Zone #3
0x72
1100 1100 (0xCC)
ALS Brightness Zone #4
0x73
1110 0110 (0xE6)
ALS Brightness Zone #5
0x74
1111 1111 (0xFF)
Group A Brightness Control Register 0xA0
1000 0000 (0x80)
Group B Brightness Control Register 0xB0
1100 0000 (0xC0)
Group C Brightness Control Register 0xC0
1111 1000 (0xF8)
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Control Register
Register Address: 0x10
MSB
ENC
bit7
EN1B
bit6
EN62
bit5
EN53
bit4
EN4A
bit3
LSB
EN3A
bit2
EN2A
bit1
EN1A
bit0
Figure 20. Diode Enable Register Description
Internal Hex Address: 0x10
Each ENx Bit controls the state of the corresponding current sink. Writing a 1 to these bits enables the current
sinks. Writing a 0 disables the current sinks. In order for current to begin flowing through the BankA current
sinks, the brightness codes stored in either the BankA Brightness register or the ALS Brightness registers (with
ALS enabled) must be non-zero. The BankA current sinks can be disabled in two different manors. Writing 0 to
the ENx bits when the current sinks are active will disable the current sinks without going through the ramp down
sequence. Additionally, setting the BankA brightness code to 0 when the current sinks are active (ENx = 1) does
force the diode current to ramp down. All ramping behavior is tied to the BankA Brightness or ALS Brightness
Register settings. Any change in these values causes the LM3535 brightness state machine to ramp the diode
current.
Writing a '1 to ENC, EN1B, EN62 and EN53 (when EN62 and EN53 are assigned to BankB) by default enables
the corresponding current sinks and drive the LEDs to the current value stored in the BankB and BankC
brightness registers. Writing a 0 to these bits immediately disables the current sinks.
The ENC and EN1B bits are ignored if the D1C/ALS pin is configured as an ALS input and if the D1B/INT is
configured as an interrupt flag.
Configuration Register
Register Address: 0x20
MSB
ALSF
bit7
ALS-EN ALS-ENB ALS-ENA
bit6
bit5
bit4
62A
bit3
LSB
53A
bit2
PWM-P PWM-EN
bit1
bit0
Figure 21. Configuration Register Description
Internal Hex Address:0x20
•
•
•
•
•
•
•
•
PWM-EN: PWM Input Enable. Writing a 1 = Enable, and a 0 = Ignore (default).
PWM-P: PWM Input Polarity. Writing a 0 = Active High (default) and a 1 = Active Low.
53A: Assign D53 diode to BankA. Writing a 0 assigns D53 to BankB (default) and a 1 assigns D53 to BankA.
62A: Assign D62 diode to BankA. Writing a 0 assigns D62 to BankB (default) and a 1 assigns D62 to BankA.
ALS-ENA: Enable ALS on BankA. Writing a 1 enables ALS control of diode current and a 0 (default) forces
the BankA current to the value stored in the BankA brightness register. The ALS-EN bit must be set to a 1 for
the ALS block to control the BankA brightness.
ALS-ENB: Enable ALS on BankB. Writing a 1 enables ALS control of diode current and a 0 (default) forces
the BankB current to the value stored in the BankB brightness register. The ALS-EN bit must be set to a 1 for
the ALS block to control the BankB brightness. The ALS function for BankB is different than bankA in that the
ALS will only enable and disable the BankB diodes depending on the ALS zone chosen by the user. BankA
utilizes the 5 different zone brightness registers (Addresses 0x70 to 0x74).
ALS-EN: Enables ALS monitoring. Writing a 1 enables the ALS monitoring circuitry and a 0 disables it. This
feature can be enabled without having the current sinks or charge pump active. The ALS value is updated in
register 0x40 (ALS Zone Register)
ALSF: ALS Interrupt Enable. Writing a 1 sets the D1B/INT pin to the ALS interrupt pin and writing a 0 (default)
sets the pin to a BankB current sink.
Options Register
Register Address: 0x30
GT1
bit7
GT0
bit6
RD2
bit5
RD1
bit4
RD0
bit3
RU2
bit2
RU1
bit1
RU0
bit0
Figure 22. Options Register
Internal Hex Address: 0x30
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RD0-RD2: Diode Current Ramp Down Step Time. : ‘000’ = 6 µs, ‘001’ = 0.77 ms, ‘010’ = 1.5 ms, ‘011’ = 3
ms, ‘100’ = 6 ms, ‘101’ = 12 ms, ‘110’ = 25ms, ‘111’ = 50ms
RU0-RU2: Diode Current Ramp Up Step Time. : ‘000’ = 6 µs, ‘001’ = 0.77 ms, ‘010’ = 1.5 ms, ‘011’ = 3 ms,
‘100’ = 6 ms, ‘101’ = 12 ms, ‘110’ = 25ms, ‘111’ = 50ms
GT0-GT1: Gain Transition Filter. The value stored in this register determines the filter time used to make a
gain transition in the event of an input line step. Filter times = ‘00’ = 3-6 ms, ‘01’ = 0.8-1.5 ms, ‘10’ = 20 µs,
On LM3535-2ALS, '11' = 1µs, On LM3535, ‘11’ = DO NOT USE
The Ramp-Up and Ramp-Down times follow the equatios: TRAMP = (NStart – NTarget) × Ramp-Step Time
DxA Brightness Control
Register Address: 0xA0
MSB
1
bit7
DxA6
bit6
DxA5
bit5
1
bit6
ALSZT2
bit5
DxA2
bit2
DxA1
bit1
ALSZT1
bit4
ALSZT0
bit3
1
bit6
1
bit5
1
bit4
1
bit3
DxA0
bit0
LSB
DxB2
bit2
DxB1
bit1
DxC Brightness Control
Register Address: 0xC0
MSB
1
bit7
DxA3
bit3
DxB Brightness Control
Register Address: 0xB0
MSB
1
bit7
DxA4
bit4
LSB
DxB0
bit0
LSB
D1C2
bit2
D1C1
bit1
D1C0
bit0
Figure 23. Brightness Control Register Description
Internal Hex Address: 0xa0 (Groupa), 0xb0 (Groupb), 0xc0 (Groupc)
NOTE
DxA6-DxA0: Sets Brightness for DxA pins (GroupA). 1111111 = Fullscale. Code 0 in this
register disables the BankA current sinks.
DxB2-DxB0: Sets Brightness for DxB pins (GroupB). 111 = Fullscale
ALSZT2-ALSZT0: Sets the Brightness Zone boundary used to enable and disable BankB
diodes based upon ambient lighting conditions.
DxC2-DxC0: Sets Brightness for D1C pin. 111 = Fullscale
The BankA Current can be approximated by Equation 1 where N = BRC = the decimal
value stored in either the BankA Brightness Register or the five different ALS Zone
Brightness Registers:
ILED (mA) | 25 x 0.85 [44 ± {(N+1)/2.91}]
Or
BRC (#) | 127+17.9 x LN(ILED(mA)/25 mA)
(1)
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Table 1. ILED vs Brightness Register Data
BankA or
ALS
Brightness
Data
% of
ILED_MAX
BankA or ALS
Brightness Data
% of ILED_MAX
BankA or ALS
Brightness Data
% of ILED_MAX
BankA or ALS
Brightness
Data
% of ILED_MAX
0000000
0.000%
0100000
0.803%
1000000
4.078%
1100000
20.713%
0000001
0.166%
0100001
0.845%
1000001
4.290%
1100001
21.792%
0000010
0.175%
0100010
0.889%
1000010
4.514%
1100010
22.928%
0000011
0.184%
0100011
0.935%
1000011
4.749%
1100011
24.122%
0000100
0.194%
0100100
0.984%
1000100
4.996%
1100100
25.379%
0000101
0.204%
0100101
1.035%
1000101
5.257%
1100101
26.701%
0000110
0.214%
0100110
1.089%
1000110
5.531%
1100110
28.092%
0000111
0.226%
0100111
1.146%
1000111
5.819%
1100111
29.556%
0001000
0.237%
0101000
1.205%
1001000
6.122%
1101000
31.096%
0001001
0.250%
0101001
1.268%
1001001
6.441%
1101001
32.716%
0001010
0.263%
0101010
1.334%
1001010
6.776%
1101010
34.420%
0001011
0.276%
0101011
1.404%
1001011
7.129%
1101011
36.213%
0001100
0.291%
0101100
1.477%
1001100
7.501%
1101100
38.100%
0001101
0.306%
0101101
1.554%
1001101
7.892%
1101101
40.085%
0001110
0.322%
0101110
1.635%
1001110
8.303%
1101110
42.173%
0001111
0.339%
0101111
1.720%
1001111
8.735%
1101111
44.371%
0010000
0.356%
0110000
1.809%
1010000
9.191%
1110000
46.682%
0010001
0.375%
0110001
1.904%
1010001
9.669%
1110001
49.114%
0010010
0.394%
0110010
2.003%
1010010
10.173%
1110010
51.673%
0010011
0.415%
0110011
2.107%
1010011
10.703%
1110011
54.365%
0010100
0.436%
0110100
2.217%
1010100
11.261%
1110100
57.198%
0010101
0.459%
0110101
2.332%
1010101
11.847%
1110101
60.178%
0010110
0.483%
0110110
2.454%
1010110
12.465%
1110110
63.313%
0010111
0.508%
0111011
2.582%
1010111
13.114%
1110111
66.611%
0011000
0.535%
0110111
2.716%
1011000
13.797%
1111000
70.082%
0011001
0.563%
0111000
2.858%
1011001
14.516%
1111001
73.733%
0011010
0.592%
0111001
3.007%
1011010
15.272%
1111010
77.574%
0011011
0.623%
0111010
3.163%
1011011
16.068%
1111011
81.616%
0011100
0.655%
0111011
3.328%
1011100
16.905%
1111100
85.868%
0011101
0.689%
0111100
3.502%
1011101
17.786%
1111101
90.341%
0011110
0.725%
0111101
3.684%
1011110
18.713%
1111110
95.048%
0011111
0.763%
0111111
3.876%
1011111
19.687%
1111111
100.000%
GroupB and GroupC Brightness Levels = 2.5, 5, 7.5, 10, 12.5, 15, 17.5, 25mA
ALS Zone Register
Register Address: 0x40
MSB
1
bit7
1
bit6
1
bit5
1
bit4
FLAG
bit3
LSB
ZONE2
bit2
ZONE1
bit1
ZONE0
bit0
Figure 24. Als Zone Register Description
Internal Hex Address: 0x40
•
•
16
ZONE0-ZONE2: ALS Zone information: '000’ = Zone0, ‘001’ = Zone1, ‘010’ = Zone2, ‘011’ = Zone3, ‘100’ =
Zone4. Other combinations not used
FLAG: ALS Transition Flag. 1 = Transition has occurred. 0 = No Transition. The FLAG bit is cleared once the
0x40 register has been read.
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ALS Control / SI Rev Register
Register Address: 0x50
MSB
ALS-EN
bit7
AVE2
bit6
AVE1
bit5
AVE0
bit4
0
bit3
LSB
0
bit2
Rev1
bit1
Rev0
bit0
Figure 25. ALS Control / Silicon Revision Register Description
Internal Hex Address: 0x50
•
•
Rev0-Rev1 : Stores the Silicon Revision value. LM3535 = 11
AVE2-AVE0: Sets Averaging Time for ALS sampling. Need two to three Averaging periods to make transition
decision. 000 = 25 ms, 001 = 50 ms, 010 = 100 ms 011 = 200 ms, 100 = 400 ms, 101 = 800 ms 110 = 1.6 s,
111 = 3.2s
Internal ALS Resistor Register
Register Address: 0x51
MSB
R3
bit7
R2
bit6
R1
bit5
R0
bit4
RFU
bit3
LSB
RFU
bit2
RFU
bit1
RFU
bit0
Figure 26. ALS Resistor Control Register Description
Internal Hex Address: 0x51
•
R0-R3: Sets the internal ALS resistor value
Table 2. Internal ALS Resistor Table
R3
R2
R1
R0
ALS RESISTOR VALUE (Ω)
0
0
0
0
High Impedance
0
0
0
1
13.6 k
0
0
1
0
9.08 k
0
0
1
1
5.47 k
0
1
0
0
2.32 k
0
1
0
1
1.99 k
0
1
1
0
1.86 k
0
1
1
1
1.65 k
1
0
0
0
1.18 k
1
0
0
1
1.1 k
1
0
1
0
1.06 k
1
0
1
1
986
1
1
0
0
804
1
1
0
1
764
1
1
1
0
745
1
1
1
1
711
Zone Boundary Registers
Register Address: 0x60, 0x61, 0x62, 0x63
MSB
ZB7
bit7
ZB6
bit6
ZB5
bit5
ZB4
bit4
ZB3
bit3
ZB2
bit2
LSB
ZB1
bit1
ZB0
bit0
Register Address:
0x60 = Zone Boundary 0
0x61 = Zone Boundary 1
0x62 = zone Boundary 2
0x63 = Zone Boundary 3
Figure 27. Zone Boundary Register Descriptions
•
ZB7-ZB0: Sets Zone Boundary Lines with a Falling ALS voltage.
– 0xFF w/ ALS Falling = 992.3 mV (typical).
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– VTRIP-LOW (typ) = [Boundary Code × 3.874mV] + 4.45mV
– For boundary codes 2 to 255. Code 0 and Code1 are mapped to equal the Code2 value.
– Each zone line has approx. 5.5mV of hysteresis between the falling and rising ALS trip points.
Zone Boundary 0 is the line between ALS Zone 0 and Zone 1. Default Code = 0x33 or approximately 200 mV
Zone Boundary 1 is the line between ALS Zone 1 and Zone 2. Default Code = 0x66 or approximately 400 mV
Zone Boundary 2 is the line between ALS Zone 2 and Zone 3. Default Code = 0x99 or approximately 600 mV
Zone Boundary 3 is the line between ALS Zone 3 and Zone 4. Default Code = 0xCC or approximately 800
mV
Zone Brightnes Registers
Register Address: 0x70, 0x71, 0x72, 0x73, 0x74
MSB
All Versions
B7
bit7
B6
bit6
B5
bit5
B4
bit4
B3
bit3
B2
bit2
LSB
B1
bit1
B0
bit0
Register Address:
0x70 = Zone 0 Brightness
0x71 = Zone 1 Brightness
0x72 = Zone 2 Brightness
0x73 = Zone 3 Brightness
0x74 = Zone 4 Brightness
Figure 28. Zone Brightness Region Register Description
•
•
•
•
•
•
18
B7-B0: Sets the ALS Zone Brightness Code. B7 always = 1 (unused). Use the formula found in the BankA
Brightness Register Description (Figure 23) to set the desired target brightness. Default values can be
overwritten
Zone0 Brightness Address = 0x70. Default = 0x99 (25) or 0.084 mA
Zone1 Brightness Address = 0x71. Default = 0xB6 (54) or 0.164 mA
Zone2 Brightness Address = 0x72. Default = 0xCC (76) or 1.45 mA
Zone3 Brightness Address = 0x73. Default = 0xE6 (102) or 6.17 mA
Zone4 Brightness Address = 0x74. Default = 0xFF (127) or 25 mA
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8 Application and Implementation
NOTE
Information in the following applications sections is not part of the TI component
specification, and TI does not warrant its accuracy or completeness. TI’s customers are
responsible for determining suitability of components for their purposes. Customers should
validate and test their design implementation to confirm system functionality.
8.1 Application Information
8.2 Typical Application
The LM3535 device is a highly integrated LED driver capable of driving 8 LEDs in parallel for large display
applications. Independent LED control allows selection of a subset of the 6 main display LEDs for partialillumination applications. In addition to the main bank of 6, the LM3535 is capable of driving an additional 2
independently controlled LEDs to support Indicator applications.
GROUP A
GROUP B
GROUP C
VIO
O
R
D1A D2A D3A D4A
D53
D62
VIN
D1B/ D1C/
INT ALS
+ -
VOUT
1µF
C1+
1µF
C1C2+
1µF
LM3535
GND
HWEN SDIO SCL PWM
1µF
C2I 2C
Control
Signals
Figure 29. LM3535 Typical Application
8.2.1 Design Requirements
A detailed design procedure is described based on a design example. For this design example, use the
parameters listed in Table 3 as the input parameters.
Table 3. Design Example Parameters
DESIGN PARAMETER
Input voltage VIN
VALUE
2.7 V to 5.5 V
LED current maximum per channel 25 mA
Operating frequency
1.33 MHz
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8.2.2 Detailed Design Procedure
8.2.2.1 Ambient Light Sensing
8.2.2.1.1 Ambient Light Sensor Block
The LM3535 incorporates an ambient light sensing interface (ALS) which translates an analog output ambient
light sensor to a user specified brightness level. The ambient light sensing circuit has 4 programmable
boundaries (ZB0 – ZB3) which define 5 ambient brightness zones. Each ambient brightness zone corresponds to
a programmable brightness threshold (Z0T – Z4T).
Furthermore, the ambient light sensing input features 15 internal software-selectable voltage setting resistors.
This allows the LM3535 the capability of interfacing with a wide selection of ambient light sensors. Additionally,
the ALS inputs can be configured as high impedance, thus providing for a true shutdown during low power
modes. The ALS resistors are selectable through the ALS Resistor Select Register (see Table 2). Figure 30
shows a functional block diagram of the ambient light sensor input.
Vdd
ALS Path Functional Diagram
Vsns
Zone
A/D
bits 8
ALS Resistor
Select Register
8 bits
ALSRS
Averager
(LPF)
Discriminator
VOUT
7 bits
0 Zline
1 Zline
2 Zline
3 Zline
Input Light
Zone
Definition
Registers
User Selectable w/
Typical Defaults
Light output
targets for
each of 5
ambient
light zones
Z0 target light
0
Z1 target light
1
Z2 target light
2
Z3 target light
3
Z4 target light
4
1
7 bits
Brightness
7 bits
Ramp
Control
ALS Select
LED Driver
0
3 bits
User Selectable w/
Typical Defaults
7 bits
3 bits
Ramp-Up Ramp-Down
Rate
Rate
Selection Selection
Figure 30. Ambient Light Sensor Functional Block Diagram
8.2.2.1.2 ALS Operation
The ambient light sensor input has a 0 to 1 V operational input voltage range. The Specifications shows the
LM3535 with an ambient light sensor (AVAGO, APDS-9005) and the internal ALS Resistor Select Register set to
0x40 (2.32 kΩ). This circuit converts 0 to 1000 LUX light into approximately a 0 to 850 mV linear output voltage.
The voltage at the active ambient light sensor input is compared against the 8 bit values programmed into the
Zone Boundary Registers (ZB0-ZB3). When the ambient light sensor output crosses one of the ZB0 – ZB3
programmed thresholds the internal ALS circuitry will smoothly transition the LED current to the new 7 bit
brightness level as programmed into the appropriate Zone Target Register (Z0T – Z4T, see Figure 28).
With bits [6:4] of the Configuration Register set to 1 (Bit6 = ALS Block Enable, Bit5 = BankB ALS Enable, Bit4 =
BankA ALS Enable), the LM3535 is configured for ambient light current Control. In this mode the ambient light
sensing input (ALS) monitors the output of analog output ambient light sensing photo diode and adjusts the LED
current depending on the ambient light. The ambient light sensing circuit has 4 configurable ambient light
boundaries (ZB0 – ZB3) programmed through the four (8-bit) Zone Boundary Registers. These zone boundaries
define 5 ambient brightness zones.
On start-up the 4 Zone Boundary Registers are pre-loaded with 0x33 (51d), 0x66 (102d), 0x99 (153d), and 0xCC
(204d). The ALS input has a 1-V active input voltage range which makes the default Zone Boundaries approx.
set at:
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Zone Boundary 0 = 200 mV
Zone Boundary 1 = 400 mV
Zone Boundary 2 = 600 mV
Zone Boundary 3 = 800 mV
These Zone Boundary Registers are all 8-bit (readable and writable) registers. By default, the first zone (Z0) is
defined between 0 and 200 mV, default for Z1 is defined between 200 mV and 400 mV, Z2 is defined between
400 mV and 600 mV, Z3 is defined between 600 mV and 800 mV, and Z4 is defined between 800 mV and 1 V.
The default settings for the 5 Zone Target Registers are 0x19, 0x33, 0x4C, 0x66, and 0x7F. This corresponds to
LED brightness settings of 84 µA, 164 µA, 1.45 mA, 6.17 mA and 25 mA of current, respectively. See Figure 31.
Vals_ref
= 1V
Full
Scale
Zone 4
ZB3
ZB1
LED Current
Vsense
Zone 3
ZB2
Zone 2
Zone 1
ZB0
Zone 0
Z0T
Ambient Light (lux)
Z1T
Z2T
Z3T
Z4T
LED Driver Input Code (0-127)
Figure 31. ALS Zone to LED Brightness Mapping
8.2.2.1.2.1 ALS Configuration Example
As an example, assume that the APDS-9005 is used as the ambient light sensing photo diode with its output
connected to the ALS input. The ALS Resistor Select Register (Address 0x51) is loaded with 0x40 which
configures the ALS input for a 2.32-kΩ internal pulldown resistor (see Table 2). This gives the output of the
APDS-9005 a typical voltage swing of 0 to 875mV with a 0 to 1k LUX change in ambient light (0.875mV/Lux).
Next, the Configuration Register (Address 0x20) is programmed with 0xDC, the ALS Control Register (Address
0x50) programmed to 0x40 and the Control Register is programmed to 0x3F . This configures the device ALS
interface for:
• Ambient Light Current Control for BankA enabled
• ALS circuitry enabled
• Assigns D53 and D62 to bankA
• Sets the ALS Averaging Time to 400 ms
Next, the Control Register (Address 0x10) is programmed with 0x3F which enables the 6 LEDs via the I2Ccompatible interface.
Now assume that the APDS-9005 ambient light sensor detects a 100 LUX ambient light at its input. This forces
the ambient light sensor output (and the ALS input) to 87.5 mV corresponding to Zone 0. Since Zone 0 points to
the brightness code programmed in Zone Target Register 0 (loaded with code 0x19), the LED current becomes:
ILED = ILED_FS u ZoneTarget0 = 25 mA u 0.336% | 84 PA.
(2)
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Next assume that the ambient light changes to 500 LUX (corresponding to an ALS voltage of 437.5 mV). This
moves the ambient light into Zone 2 which corresponds to Zone Target Register 2 (loaded with code 0x4C) the
LED current then becomes:
ILED = ILED_FS u ZoneTarget2 = 25 mA u 5.781% | 1.45 mA
(3)
8.2.2.1.3 ALS Averaging Time
The ALS averaging time is the time over which the averager block collects samples from the A/D converter and
then averages them to pass to the discriminator block (see Figure 32). Ambient light sensor samples are
averaged and then further processed by the discriminator block to provide rejection of noise and transient
signals. The averager is configurable with 8 different averaging times to provide varying amounts of noise and
transient rejection (see Figure 25). The discriminator block algorithm has a maximum latency of two averaging
cycles, therefore the averaging time selection determines the amount of delay that will exist between a steady
state change in the ambient light conditions and the associated change of the backlight illumination. For
example, the A/D converter samples the ALS inputs at 16 kHz. If the averaging time is set to 800 ms, the
averager sends the updated zone information to the discriminator every 800 ms. This zone information contains
the average of approximately 12800 samples (800 ms × 16 kHz). Due to the latency of 2 averaging cycles, when
there is a steady-state change in the ambient light, the LED current begins to transition to the appropriate target
value after approximately 1600 ms have elapsed.
The sign and magnitude of these averager outputs are used to determine whether the LM3535 should change
brightness zones. The averager block follows the following rules to make a zone transition:
• The averager always begins with a Zone0 reading stored at start-up. If the main display LEDs are active
before the ALS block is enabled, it is recommended that the ALS-EN bit be enabled at least 3 averaging
cycles times before the ALS-ENA bit is enabled.
• The averager always rounds down to the lower zone in the case of a non-integer zone average (1.2 rounds to
1 and 1.75 also rounds to 1). Figure 32 shows an example of how the Averager will make the zone decisions
for different ambient conditions.
Zone4
Zone3
Zone2
Zone1
Zone0
Zone
Average
Averager
Output
1.0
1.75
3.5
4.0
2.25
2.25
1.5
1
1
3
4
2
2
1
Figure 32. Averager Calculation
•
•
•
•
•
The two most current averaging samples are used to make zone change decisions.
To make a zone change, data from three averaging cycles are needed (starting value, first transition, second
transition or rest).
To Increase the brightness zone, a positive averager zone output must be followed by a second positive
averager output or a repeated Averager zone. ('+' to '+' or '+' to 'Rest')
To decrease the brightness zone, a negative averager zone output must be followed by a second negative
averager output or a repeated Averager zone. ('-' to '-' or '-' to 'Rest')
In the case of two increases or decreases in the averager output, the LM3535 transitions to zone equal to the
last averager output.
Figure 33 provides a graphical representation of the behavior of the averager.
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Averager Output
µ5¶ = Rest, µ+¶ = Increase, µ-µ = Decrease
Zone4
Zone3
Zone2
Zone1
Zone0
R
Brightness
Zone
+
0
R
0
+
1
+
1
+
3
R
4
R
4
4
Zone4
Zone3
Zone2
Zone1
Zone0
R
Brightness
Zone
4
R
4
3
3
1
R
0
R
0
0
Zone4
Zone3
Zone2
Zone1
Zone0
R
Brightness
Zone
+
0
+
0
4
+
4
4
4
R
1
1
Figure 33. Brightness Zone Change Examples
Using the diagram for the ALS block (Figure 30), Figure 34 shows the flow of information starting with the A/D,
transitioning to the averager, followed by the discriminator. Each state filters the previous output to help prevent
unwanted zone to zone transitions.
1 Ave
Period
ALS Input
Zone4
Zone3
Zone2
Zone1
Zone0
Averager Output
Zone4
Zone3
Zone2
Zone1
Zone0
LED Brightness
Zone
Zone4
Zone3
Zone2
Zone1
Zone0
Figure 34. Ambient Light Input To Backlight Mapping
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When using the ALS averaging functionality, it is important to remember that the averaging cycle is free running
and is not synchronized with changing ambient lighting conditions. Due to the nature of the averager round down,
an increase in brightness can take between 2 and 3 averaging cycles to change zones while a decrease in
brightness can take between 1 and 2 averaging cycles to change. See Figure 25 for a list of possible averager
periods. Figure 35 shows an example of how the perceived brightness change time can vary.
1 Ave
Period
Zone4
Zone3
Zone2
Zone1
Zone0
Averager
Output
1
1
3
4
tBRGT-CHANGE =
2.75 Average
Time
2
2
1
tBRGT-CHANGE =
1.75 Average
Time
Figure 35. Perceived Brightness Change Time
8.2.2.1.4 Ambient Light Current Control + PWM
The ambient light current control can also be a function of the PWM input duty cycle. Assume the LM3535 is
configured as described in the previous example, but this time the Enable PWM bit set to 1 (Configuration
Register bit [0]). Figure 36 shows how the different blocks (PWM and ALS) influence the LED current.
Active Zone
Target
Register
BRT
Register
Dig Code
7 bits
1
7 bits
LED Ramp
Rate Control
DAC
7 bits
0
7 bits
Note 1
3 bits
ALS Select
Ramp Rate
Increasing
ACODE
3 bits
VOUT
Ramp Rate
Decreasing
IFS = 25 mA
Full Scale
Current
LED
Driver
ILED
PWM Polarity Bit
(0 = active high,
1 = active low)
Note 3
EN_PWM bit
PWM
Note 2
DPWM
Note 1: ACODE Is a Scaler between 0 and 1 based on the Brightness Data or Zone Target Data Depending on the ALS Select Bit
Note 2: DPWM Is a Scaler between 0 and 1 and corresponds to the duty cycle of the PWM input signal
Note 3: For EN_PWM bit = 1
ILED = IFS x ACODE x DPWM
For EN_PWM bit = 0
ILED = IFS x ACODE
Figure 36. Current Control Block Diagram
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8.2.2.1.4.1 ALS + PWM Example
In this example, the APDS-9005 sensor detects that the ambient light has changed to 1 kLux. The voltage at the
ALS input is now approximately 875 mV and the ambient light falls within Zone 5. This causes the LED
brightness to be a function of Zone Target Register 5 (loaded with 0x7F). Now assume the PWM input is also
driven with a 50% duty cycle pulsed waveform. The LED current now becomes:
ILED = ILED_FS u ZoneTarget5 u D = 25 mA u 100% u 50% | 12.5 mA
(4)
8.2.2.2 LED Configurations
The LM3535 has a total of 8 current sinks capable of sinking 200 mA of total diode current. These 8 current sinks
are configured to operate in three independently controlled lighting regions. GroupA has four dedicated current
sinks, while GroupB and GroupC each have one. To add greater lighting flexibility, the LM3535 has two
additional drivers (D53 and D62) that can be assigned to either GroupA or GroupB through a setting in the
general purpose register.
At start-up, the default condition is four LEDs in GroupA, three LEDs in GroupB and a single LED in GroupC
(NOTE: GroupC only consists of a single current sink (D1C) under any configuration). Bits 53A and 62A in the
general purpose register control where current sinks D53 and D62 are assigned. By writing a 1 to the 53A or 62A
bits, D53 and D62 become assigned to the GroupA lighting region. Writing a 0 to these bits assigns D53 and
D62 to the GroupB lighting region. With this added flexibility, the LM3535 is capable of supporting applications
requiring 4, 5, or 6 LEDs for main display lighting, while still providing additional current sinks that can be used
for a wide variety of lighting functions.
8.2.2.3 Maximum Output Current, Maximum LED Voltage, Minimum Input Voltage
The LM3535 can drive 8 LEDs at 25 mA each (GroupA , GroupB, GroupC) from an input voltage as low as 3.2 V,
as long as the LEDs have a forward voltage of 3.6 V or less (room temperature).
The statement above is a simple example of the LED drive capability of the LM3535. The statement contains the
key application parameters that are required to validate an LED-drive design using the LM3535: LED current
(ILEDx), number of active LEDs (Nx), LED forward voltage (VLED), and minimum input voltage (VIN-MIN).
Equation 5 and Equation 6 can be used to estimate the maximum output current capability of the LM3535:
ILED_MAX = [(1.5 x VIN) – VLED – (IADDITIONAL × ROUT)] / [(Nx × ROUT) + kHRx]
ILED_MAX = [(1.5 x VIN ) - VLED – (IADDITIONAL × 2.4 Ω)] / [(Nx × 2.4 Ω) + kHRx]
(5)
(6)
IADDITIONAL is the additional current that could be delivered to the other LED groups.
ROUT – Output resistance. This parameter models the internal losses of the charge pump that result in voltage
droop at the pump output VOUT. Since the magnitude of the voltage droop is proportional to the total output
current of the charge pump, the loss parameter is modeled as a resistance. The output resistance of the LM3535
is typically 2.4 Ω (VIN = 3.6 V, TA = 25°C) — see Equation 7:
VVOUT = (1.5 × VIN) – [(NA × ILEDA + NB × ILEDB + NC × ILEDC) × ROUT]
(7)
kHR – Headroom constant. This parameter models the minimum voltage required to be present across the current
sinks for them to regulate properly. This minimum voltage is proportional to the programmed LED current, so the
constant has units of mV/mA. The typical kHR of the LM3535 is 4mV/mA — see Equation 8:
(VVOUT – VLEDx) > kHRx × ILEDx
Typical Headroom Constant Values kHRA = kHRB = kHRC = 4 mV/mA
(8)
(9)
Equation 5 is obtained from combining Equation 7 (the ROUT equation) with Equation 8 (the kHRx equation) and
solving for ILEDx. Maximum LED current is highly dependent on minimum input voltage and LED forward voltage.
Output current capability can be increased by raising the minimum input voltage of the application, or by
selecting an LED with a lower forward voltage. Excessive power dissipation may also limit output current
capability of an application.
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8.2.2.3.1 Total Output Current Capability
The maximum output current that can be drawn from the LM3535 is 200 mA.
DRIVER TYPE
MAXIMUM Dxx CURRENT
DxA
25 mA per DxA pin
DxB
25 mA per DxB pin
D1C
25 mA
8.2.2.4 Parallel Connected and Unused Outputs
Connecting the outputs in parallel does not affect internal operation of the LM3535 and has no impact on the
Electrical Characteristics and limits previously presented. The available diode output current, maximum diode
voltage, and all other specifications provided in the Electrical Characteristics table apply to this parallel output
configuration, just as they do to the standard LED application circuit.
All Dx current sinks utilize LED forward voltage sensing circuitry to optimize the charge-pump gain for maximum
efficiency. Due to the nature of the sensing circuitry, TI recommends not leaving any of the Dx pins open when
the current sinks are enabled (ENx bits are set to 1). Leaving Dx pins unconnected forces the charge-pump into
3/2× mode over the entire VIN range negating any efficiency gain that could have been achieved by switching to
1× mode at higher input voltages.
If the D1B or D1C drivers are not going to be used, make sure that the ENB and ENC bits in the general purpose
register are set to 0 to ensure optimal efficiency.
8.2.2.5 Power Efficiency
Efficiency of LED drivers is commonly taken to be the ratio of power consumed by the LEDs (PLED) to the power
drawn at the input of the part (PIN). With a 3/2× – 1× charge pump, the input current is equal to the charge pump
gain times the output current (total LED current). The efficiency of the LM3535 can be predicted as follow:
PLEDTOTAL = (VLEDA × NA × ILEDA) + (VLEDB × NB × ILEDB) + (VLEDC × ILEDC)
PIN = VIN × IIN
PIN = VIN × (GAIN × ILEDTOTAL + IQ)
E = (PLEDTOTAL / PIN)
(10)
(11)
(12)
(13)
The LED voltage is the main contributor to the charge-pump gain selection process. Use of low forward-voltage
LEDs (3 V to 3.5 V) allows the LM3535 to stay in the gain of 1× for a higher percentage of the lithium-ion battery
voltage range when compared to the use of higher forward voltage LEDs (3.5 V to 4 V). See LED Forward
Voltage Monitoring for a more detailed description of the gain selection and transition process.
For an advanced analysis, TI recommends that power consumed by the circuit (VIN x IIN) for a given load be
evaluated rather than power efficiency.
8.2.2.6 Power Dissipation
The power dissipation (PDISS) and junction temperature (TJ) can be approximated with the equations below. PIN is
the power generated by the 3/2× – 1× charge pump, PLED is the power consumed by the LEDs, TA is the ambient
temperature, and RθJA is the junction-to-ambient thermal resistance for the DSBGA 20-bump package. VIN is the
input voltage to the LM3535, VLED is the nominal LED forward voltage, N is the number of LEDs and ILED is the
programmed LED current.
PDISS = PIN – PLEDA - PLEDB – PLEDC
PDISS= (GAIN × VIN × IGroupA + GroupB + GroupC ) – (VLEDA × NA × ILEDA) – (VLEDB × NB × ILEDB) – (VLEDC × ILEDC)
TJ = TA + (PDISS x RθJA)
(14)
(15)
(16)
The junction temperature rating takes precedence over the ambient temperature rating. The LM3535 may be
operated outside the ambient temperature rating, so long as the junction temperature of the device does not
exceed the maximum operating rating of 110°C. The maximum ambient temperature rating must be derated in
applications where high power dissipation and/or poor thermal resistance causes the junction temperature to
exceed 110°C.
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8.2.2.7 Thermal Protection
Internal thermal protection circuitry disables the LM3535 when the junction temperature exceeds 150°C (typical).
This feature protects the device from being damaged by high die temperatures that might otherwise result from
excessive power dissipation. The device recovers and operates normally when the junction temperature falls
below 125°C (typical). It is important that the board layout provide good thermal conduction to keep the junction
temperature within the specified operating ratings.
8.2.2.8 Capacitor Selection
The LM3535 requires 4 external capacitors for proper operation (C1 = C2 = CIN = COUT = 1 µF). Surface-mount
multi-layer ceramic capacitors are recommended. These capacitors are small, inexpensive and have very low
equivalent series resistance (ESR < 20 mΩ typical). Tantalum capacitors, OS-CON capacitors, and aluminum
electrolytic capacitors are not recommended for use with the LM3535 due to their high ESR, as compared to
ceramic capacitors.
For most applications, ceramic capacitors with X7R or X5R temperature characteristic are preferred for use with
the LM3535. These capacitors have tight capacitance tolerance (as good as ±10%) and hold their value over
temperature (X7R: ±15% over –55°C to 125°C; X5R: ±15% over –55°C to 85°C).
Capacitors with Y5V or Z5U temperature characteristic are generally not recommended for use with the LM3535.
Capacitors with these temperature characteristics typically have wide capacitance tolerance (+80%, –20%) and
vary significantly over temperature (Y5V: +22%, –82% over –30°C to +85°C range; Z5U: +22%, –56% over
+10°C to +85°C range). Under some conditions, a nominal 1µF Y5V or Z5U capacitor could have a capacitance
of only 0.1 µF. Such detrimental deviation is likely to cause Y5V and Z5U capacitors to fail to meet the minimum
capacitance requirements of the LM3535.
The recommended voltage rating for the capacitors is 10 V to account for DC bias capacitance losses.
8.2.3 Application Curves
100
180
4 LEDs @ 25 mA each
VLED = 3.6V
170
90
160
VLED = 3.6V
VLED = 3.3V
140
130
ηLED (%)
IIN (mA)
150
VLED = 3.0V
120
80
70
110
100
60
90
80
2.7
VLED = 3.3V
4 LEDs @ 25 mA Each
3.1
3.5
3.9
4.3
4.7
5.1
VLED = 3.0V
50
2.7
5.5
VIN (V)
3.1
3.5
3.9 4.3
VIN (V)
4.7
5.1
5.5
Figure 37. Input Current vs Input Voltage 4 LEDs
Figure 38. LED Drive Efficiency vs Input Voltage 4 LEDs
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260
100
6 LEDs @ 25 mA each
VLED = 3.6V
240
90
VLED = 3.3V
200
VLED = 3.0V
VLED = 3.6V
80
LED (%)
IIN (mA)
220
70
180
VLED = 3.3V
60
160
VLED = 3.0V
6 LEDs @ 25 mA Each
140
2.7
3.1
3.5
3.9
4.3
4.7
5.1
50
2.7
5.5
3.1
3.5
3.9
VIN (V)
4.3
4.7
5.1
5.5
VIN (V)
Figure 39. Input Current vs Input Voltage 6 LEDs
Figure 40. LED Drive Efficiency vs Input Voltage 6 LEDs
100
340
8 LEDs @ 25 mA each
VLED = 3.6V
90
300
VLED = 3.6V
260
ηLED (%)
IIN (mA)
VLED = 3.3V
VLED = 3.0V
80
70
220
60
VLED = 3.3V
VLED = 3.0V
8 LEDs @ 25 mA Each
180
2.7
3.1
3.5
3.9 4.3
VIN (V)
4.7
5.1
50
2.7
5.5
Figure 41. Input Current vs Input Voltage 8 LEDs
3.5
3.9 4.3
VIN (V)
4.7
5.1
5.5
Figure 42. LED Drive Efficiency vs Input Voltage 8 LEDs
1.0
100
6 LEDs @ 25 mA each
VLED = 3.3V
0.9
0.8
IDX MATCHING (%)
90
LED (%)
3.1
80
70
TA = +85°C
60
0.6
0.5
TA = -30°C
0.4
TA = +25°C
0.3
0.2
TA = -30°C and +25°C
50
2.7
TA = +85°C
0.7
3.1
3.5
3.9
4.3
4.7
5.1
BRC = 127
6 LEDs in BankA
0.1
5.5
0.0
2.7
VIN (V)
Figure 43. LED Drive Efficiency vs Input Voltage Tri-Temp
6 LEDs
3.1
3.5
3.9 4.3
VIN (V)
4.7
5.1
5.5
Figure 44. ILED Matching vs Input Voltage 6 LEDs
9 Power Supply Recommendations
The LM3535 is designed to operate from an input voltage supply range between 2.7 V and 5.5 V. This input
supply must be well regulated and capable to supply the required input current. If the input supply is located far
from the LM3535 additional bulk capacitance may be required in addition to the ceramic bypass capacitors.
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Product Folder Links: LM3535
LM3535
www.ti.com
SNVS598B – AUGUST 2010 – REVISED MARCH 2018
10 Layout
10.1 Layout Guidelines
Proper board layout helps to ensure optimal performance of the LM3535 circuit. The following guidelines are
recommended:
• Place capacitors as close as possible to the LM3535, preferably on the same side of the board as the device.
• Use short, wide traces to connect the external capacitors to the LM3535 to minimize trace resistance and
inductance.
• Use a low resistance connection between ground and the GND pins of the LM3535. Using wide traces and/or
multiple vias to connect GND to a ground plane on the board is most advantageous.
10.2 Layout Example
Figure 45. Minimum Layout
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Product Folder Links: LM3535
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LM3535
SNVS598B – AUGUST 2010 – REVISED MARCH 2018
www.ti.com
11 Device and Documentation Support
11.1 Receiving Notification of Documentation Updates
To receive notification of documentation updates, navigate to the device product folder on ti.com. In the upper
right corner, click on Alert me to register and receive a weekly digest of any product information that has
changed. For change details, review the revision history included in any revised document.
11.2 Community Resources
The following links connect to TI community resources. Linked contents are provided "AS IS" by the respective
contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of
Use.
TI E2E™ Online Community TI's Engineer-to-Engineer (E2E) Community. Created to foster collaboration
among engineers. At e2e.ti.com, you can ask questions, share knowledge, explore ideas and help
solve problems with fellow engineers.
Design Support TI's Design Support Quickly find helpful E2E forums along with design support tools and
contact information for technical support.
11.3 Trademarks
E2E is a trademark of Texas Instruments.
All other trademarks are the property of their respective owners.
11.4 Electrostatic Discharge Caution
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more
susceptible to damage because very small parametric changes could cause the device not to meet its published specifications.
11.5 Glossary
SLYZ022 — TI Glossary.
This glossary lists and explains terms, acronyms, and definitions.
12 Mechanical, Packaging, and Orderable Information
The following pages include mechanical, packaging, and orderable information. This information is the most
current data available for the designated devices. This data is subject to change without notice and revision of
this document. For browser-based versions of this data sheet, refer to the left-hand navigation.
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Product Folder Links: LM3535
PACKAGE OPTION ADDENDUM
www.ti.com
10-Dec-2020
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
(4/5)
(6)
LM3535TME/NOPB
ACTIVE
DSBGA
YFQ
20
250
RoHS & Green
SNAGCU
Level-1-260C-UNLIM
-30 to 85
3535
LM3535TMX/NOPB
ACTIVE
DSBGA
YFQ
20
3000
RoHS & Green
SNAGCU
Level-1-260C-UNLIM
-30 to 85
3535
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of
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