EVALUATION KIT AVAILABLE
MAX8739
TFT, LCD, DC-DC Converter with
Operational Amplifiers
General Description
The MAX8739 includes a high-performance, step-up
regulator and two high-current operational amplifiers
for active-matrix thin-film transistor (TFT) liquid-crystal
displays (LCDs). The input supply voltage range of
the MAX8739 is from 1.8V to 5.5V. The device also
includes a logic-controlled, high-voltage switch with
adjustable delay.
The step-up DC-DC converter provides the regulated
supply voltage for the panel source driver ICs. The converter is a high-frequency (600kHz/1.2MHz) current-mode
regulator with an integrated 14V n-channel MOSFET
that allows the use of ultra-small inductors and ceramic
capacitors. It provides fast transient response to pulsed
loads while achieving efficiencies over 85%.
The two high-performance operational amplifiers are
designed to drive the LCD backplane (VCOM) and/or the
gamma-correction-divider string. The devices feature high
output current (±150mA), fast slew rate (7.5V/µs), wide
bandwidth (12MHz), and rail-to-rail inputs and outputs.
The MAX8739 is available in a 20-pin, 5mm x 5mm TQFN
package with a maximum thickness of 0.8mm for ultrathin LCD panels.
Applications
Features
●● 1.8V to 5.5V Input Supply Range
●● 600kHz/1.2MHz Current-Mode Step-Up Regulator
• Fast Transient Response to Pulsed Load
• High-Accuracy Output Voltage (1.5%)
• Built-In 14V, 1.9A, 0.2Ω n-Channel MOSFET
• High Efficiency (> 85%)
• Digital Soft-Start
●● Two High-Performance Operational Amplifiers
• ±150mA Output Short-Circuit Current
• 7.5V/µs Slew Rate
• 12MHz, -3dB Bandwidth
• Rail-to-Rail Inputs/Outputs
●● Logic-Controlled, High-Voltage Switch with Adjustable
Delay
●● Built-In Power-Up Sequence
●● Input Supply Undervoltage Lockout
●● Timer Delay Fault Latch for All Regulator Outputs
●● Thermal-Overload Protection
Simplified Operating Circuit
VIN
+1.8V TO +5.5V
●● Notebook Computer Displays
●● LCD Monitor Panels
LX
IN
TEMP RANGE
FB
MAX8739
Ordering Information
PART
VMAIN
PIN-PACKAGE
MAX8739ETP+
-40°C to +85°C
20 TQFN-EP*
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pads.
FREQ
AGND
COMP
PGND
SUP
NEG1
TO VCOM
BACKPLANE
OUT1
NEG2
POS1
OUT2
POS2
LDO
Pin Configuration appears at end of data sheet.
DEL
SRC
DRN
FROM TCON
19-3983; Rev 1; 7/14
CTL
COM
MAX8739
TFT, LCD, DC-DC Converter with
Operational Amplifiers
Absolute Maximum Ratings
IN, CTL, FREQ, LDO to AGND................................-0.3V to +6V
COMP, FB, DEL to AGND....................... -0.3V to (VLDO + 0.3V)
PGND to AGND...................................................................±0.3V
LX to PGND...........................................................-0.3V to +14V
SUP to AGND.........................................................-0.3V to +14V
POS1, POS2, NEG1, NEG2, OUT1,
OUT2 to AGND.................................... -0.3V to (VSUP + 0.3V)
SRC to AGND........................................................-0.3V to +30V
COM, DRN to AGND............................... -0.3V to (VSRC + 0.3V)
COM RMS Output Current................................................±50mA
OUT1, OUT2 Maximum Continuous Output Current........±75mA
LX Switch Maximum Continuous RMS Output Current........1.6A
Continuous Power Dissipation (TA = +70°C)
20-Pin, 5mm x 5mm, TQFN (derate 20.8mW/°C
above +70°C).............................................................1667mW
Operating Temperature Range............................ -40°C to +85°C
Junction Temperature..........................................................+150°
Storage Temperature Range............................. -65°C to +150°C
Lead Temperature (soldering, 10s).................................. +300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these
or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect
device reliability.
Electrical Characteristics
(VIN = 2.5V, VSUP = 10V, VSRC = 28V, FREQ = CTL = IN, PGND = AGND = 0, TA = 0°C to +85°C. Typical values are at TA = +25°C,
unless otherwise noted.)
PARAMETER
CONDITIONS
IN Supply Range
MIN
TYP
MAX
UNITS
5.5
V
15
30
µA
1.30
1.75
V
1.8
IN Quiescent Current
VIN = 2.5V, VFB = 1.5V
IN Undervoltage Lockout
Threshold
IN rising, 200mV hysteresis
LDO Output Voltage
6V ≤ VSUP ≤ 13V, ILDO = 12.5mA
4.6
5
5.4
V
LDO Undervoltage Lockout
Threshold
LDO rising, 200mV hysteresis
2.4
2.7
3.0
V
LDO Output Current
15
SUP Supply Voltage Range
4.5
mA
SUP Undervoltage Fault
Threshold
SUP Supply Current
VPOS_ = 4V, no load
Thermal Shutdown
Rising edge, 15°C hysteresis
13.0
V
1.4
V
LX not switching
1.8
3.0
LX switching
16
30
+160
mA
°C
STEP-UP REGULATOR
Operating Frequency
Maximum Duty Cycle
FREQ Input Low Voltage
FREQ Input High Voltage
FREQ = AGND
512
600
768
FREQ = IN
1020
1200
1380
FREQ = AGND
91
95
99
FREQ = IN
88
92
96
VIN = 1.8V to 5.5V
0.6
VIN = 1.8V to 2.4V
1.4
VIN = 2.4V to 5.5V
2.0
kHz
%
V
V
FREQ Pulldown Current
VFREQ = 1.0V
3.5
5.0
6.0
µA
FB Regulation Voltage
ISWITCH = 200mA
1.225
1.240
1.255
V
FB Fault Trip Level
Falling edge
0.96
1.00
1.04
V
Duration to Trigger Fault
Condition
FREQ = AGND
43
51
64
FREQ = IN
47
55
65
www.maximintegrated.com
ms
Maxim Integrated │ 2
MAX8739
TFT, LCD, DC-DC Converter with
Operational Amplifiers
Electrical Characteristics (continued)
(VIN = 2.5V, VSUP = 10V, VSRC = 28V, FREQ = CTL = IN, PGND = AGND = 0, TA = 0°C to +85°C. Typical values are at TA = +25°C,
unless otherwise noted.)
PARAMETER
CONDITIONS
MIN
TYP
FB Load Regulation
0 < ILOAD < 200mA, transient only
FB Line Regulation
VIN = 1.8V to 5.5V
FB Input Bias Current
VFB = 1.3V
FB Transconductance
DICOMP = 5µA
FB Voltage Gain
FB to COMP
700
LX On-Resistance
ILX = 200mA
200
LX Leakage Current
VLX = VSUP = 13V
LX Current Limit
VFB = 1.1V, duty cycle = 65%
-0.15
75
Current-Sense Transresistance
Soft-Start Period
MAX
-1
UNITS
%
-0.08
+0.15
%/V
125
200
nA
160
280
µS
V/V
400
mΩ
0.01
20
µA
1.5
1.9
2.3
A
0.22
0.36
0.50
V/A
FREQ = AGND
13
FREQ = IN
14
Soft-Start Step Size
ms
0.24
A
OPERATIONAL AMPLIFIERS
Input Offset Voltage
VCM = VSUP/2, TA = +25°C
Input Bias Current
NEG1, POS1, NEG2, POS2
-50
Input Common-Mode Voltage
Range
NEG1, POS1, NEG2, POS2
0
Common-Mode Rejection Ratio
0 ≤ VNEG_, VPOS_ ≤ VSUP
50
Open-Loop Gain
Output Voltage Swing High
Output Voltage Swing Low
0
12
mV
+1
+50
nA
VSUP
V
90
dB
125
dB
IOUT_ = 100µA
VSUP 15
VSUP
-2
IOUT_ = 5mA
VSUP 150
VSUP 80
mV
IOUT_ = -100µA
2
15
IOUT_ = -5mA
80
150
Source
50
150
Sink
50
140
Short-Circuit Current
To VSUP/2
Output Source-and-Sink Current
Buffer configuration, VPOS_ = 4V, |DVOS| < 10mV
40
Power-Supply Rejection Ratio
DC, 6V ≤ VSUP ≤ 13V, VPOS_, VNEG_ = VSUP/2
60
Slew Rate
mV
mA
mA
100
dB
7.5
V/µs
-3dB Bandwidth
RL = 10kΩ, CL = 10pF, buffer configuration
12
MHz
Gain-Bandwidth Product
Buffer configuration
8
MHz
POSITIVE GATE-DRIVER TIMING AND CONTROL SWITCHES
DEL Capacitor Charge Current
During startup, VDEL = 1V
DEL Turn-On Threshold
DEL Pin Discharge Switch OnResistance
During UVLO, VIN = 1.3V
CTL Input-Low Voltage
VIN = 1.8V to 5.5V
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4
5
6
µA
1.178
1.24
1.302
V
20
Ω
0.6
V
Maxim Integrated │ 3
MAX8739
TFT, LCD, DC-DC Converter with
Operational Amplifiers
Electrical Characteristics (continued)
(VIN = 2.5V, VSUP = 10V, VSRC = 28V, FREQ = CTL = IN, PGND = AGND = 0, TA = 0°C to +85°C. Typical values are at TA = +25°C,
unless otherwise noted.)
PARAMETER
CTL Input-High Voltage
CTL Input-Leakage Current
CTL-to-SRC Propagation Delay
CONDITIONS
MIN
VIN = 1.8V to 2.4V
1.4
VIN = 2.4V to 5.5V
2.0
CTL = AGND or IN
-1
TYP
MAX
UNITS
V
+1
COM falling, no load on COM
100
COM rising, no load on COM
100
SRC Input-Voltage Range
µA
ns
28
V
VDRN = 8V, CTL = AGND, VDEL = 1.5V
15
30
VDRN = 8V, CTL = IN, VDEL = 1.5V
100
180
DRN Input Current
VDRN = 8V, CTL = AGND, VDEL = 1.5V
90
150
µA
SRC-to-COM Switch OnResistance
VDEL = 1.5V, CTL = IN
15
30
Ω
DRN-to-COM Switch OnResistance
VDEL = 1.5V, CTL = AGND
30
60
Ω
SRC Input Current
µA
Electrical Characteristics
(VIN = 2.5V, VSUP = 10V, VSRC = 28V, FREQ = CTL = IN, PGND = AGND = 0, TA = -40°C to +85°C, unless otherwise noted.) (Note 1)
PARAMETER
CONDITIONS
IN Supply Range
MIN
1.8
IN Quiescent Current
VIN = 2.5V, VFB = 1.5V
IN Undervoltage Lockout
Threshold
IN rising, 200mV hysteresis
LDO Output Voltage
6V ≤ VSUP ≤ 13V, ILDO = 12.5mA
LDO Undervoltage Lockout
Threshold
LDO rising, 200mV hysteresis
UNITS
V
30
µA
1.75
V
4.6
5.4
V
2.4
3.0
V
15
SUP Supply Voltage Range
4.5
SUP Undervoltage Fault
Threshold
VPOS_ = 4V, no load
MAX
5.5
LDO Output Current
SUP Supply Current
TYP
mA
13.0
V
1.4
V
LX not switching
3.0
LX switching
30
mA
STEP-UP REGULATOR
Operating Frequency
Maximum Duty Cycle
FREQ Input Low Voltage
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FREQ = AGND
512
768
FREQ = IN
1020
1380
FREQ = AGND
91
99
FREQ = IN
88
96
VIN = 1.8V to 5.5V
0.6
kHz
%
V
Maxim Integrated │ 4
MAX8739
TFT, LCD, DC-DC Converter with
Operational Amplifiers
Electrical Characteristics (continued)
(VIN = 2.5V, VSUP = 10V, VSRC = 28V, FREQ = CTL = IN, PGND = AGND = 0, TA = -40°C to +85°C, unless otherwise noted.) (Note 1)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
VIN = 1.8V to 2.4V
1.4
VIN = 2.4V to 5.5V
2.0
FREQ Pulldown Current
VFREQ = 1.0V
3.5
6.0
µA
FB Regulation Voltage
ISWITCH = 200mA
1.220
1.260
V
FB Fault-Trip Level
Falling edge
0.96
1.04
V
Duration to Trigger-Fault
Condition
FREQ = AGND
41
64
FREQ = IN
47
65
FB Line Regulation
VIN =1.8V to 5.5V
-0.15
+0.15
%/V
FB Input Bias Current
VFB = 1.3V
200
nA
FB Transconductance
DICOMP = 5µA
280
µS
LX On-Resistance
ILX = 200mA
400
mΩ
LX Current Limit
VFB = IV, duty cycle = 65%
FREQ Input-High Voltage
75
Current-Sense Transresistance
V
ms
1.5
2.3
A
0.22
0.50
V/A
12
mV
VSUP
V
OPERATIONAL AMPLIFIERS
Input Offset Voltage
VCM = VSUP/2, TA = +25°C
Input Common-Mode Voltage
Range
NEG1, POS1, NEG2, POS2
0
Common-Mode Rejection Ratio
0 ≤ VNEG_, VPOS_ ≤ VSUP
50
Output Voltage Swing High
Output Voltage Swing Low
IOUT_ = 100µA
VSUP 15
IOUT_ = 5mA
VSUP 150
dB
mV
IOUT_ = -100µA
15
IOUT_ = -5mA
150
Source
50
Sink
50
mV
Short-Circuit Current
To VSUP/2
Output Source-and-Sink Current
Buffer configuration, VPOS_ = 4V, |DVOS| < 10mV
40
mA
Power-Supply Rejection Ratio
DC, 6V ≤ VSUP ≤ 13V, VPOS_, VNEG_ = VSUP/2
60
dB
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mA
Maxim Integrated │ 5
MAX8739
TFT, LCD, DC-DC Converter with
Operational Amplifiers
Electrical Characteristics (continued)
(VIN = 2.5V, VSUP = 10V, VSRC = 28V, FREQ = CTL = IN, PGND = AGND = 0, TA = -40°C to +85°C, unless otherwise noted.) (Note 1)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
4
6
µA
1.178
1.302
V
0.6
V
POSITIVE GATE-DRIVER TIMING AND CONTROL SWITCHES
DEL Capacitor Charge Current
During startup, VDEL = 1V
DEL Turn-On Threshold
CTL Input-Low Voltage
VIN = 1.8V to 5.5V
CTL Input-High Voltage
VIN = 1.8V to 2.4V
1.4
VIN = 2.4V to 5.5V
2.0
V
SRC Input-Voltage Range
28
V
VDRN = 8V, CTL = AGND, VDEL = 1.5V
30
VDRN = 8V, CTL = IN, VDEL = 1.5V
180
DRN Input Current
VDRN = 8V, CTL = AGND, VDEL = 1.5V
150
µA
SRC-to-COM Switch
On-Resistance
VDEL = 1.5V, CTL = IN
30
Ω
DRN-to-COM Switch
On-Resistance
VDEL = 1.5V, CTL = AGND
60
Ω
SRC Input Current
µA
Note 1: Specifications to -40°C are guaranteed by design, not production tested.
Typical Operating Characteristics
(Circuit of Figure 1, VIN = 2.5V, VMAIN = 8V, FREQ = IN, TA = +25°C, unless otherwise noted.)
70
60
VIN = 3.3V
50
40
30
VIN = 1.8V
20
fSW = 1.2MHz
VOUT = 8V
L = 3.0µH
10
0
1
10
100
LOAD CURRENT (mA)
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1000
VIN = 3.3V
70
60
50
40
VIN = 1.8V
30
20
fSW = 600MHz
VOUT = 8V
L = 6.2µH
10
0
1
10
100
LOAD CURRENT (mA)
1000
0.5
MAX8739 toc03
80
EFFICIENCY (%)
EFFICIENCY (%)
80
VIN = 5V
90
STEP-UP REGULATOR
LOAD REGULATION
VOLTAGE ACCURACY (%)
VIN = 5V
90
100
MAX8739 toc01
100
STEP-UP REGULATOR EFFICIENCY
vs. LOAD CURRENT
MAX8739 toc02
STEP-UP REGULATOR EFFICIENCY
vs. LOAD CURRENT
0
-0.5
VIN = 1.8V
-1.0
VIN = 5V
-1.5
VIN = 3.3V
-2.0
-2.5
fSW = 1.2MHz
VOUT = 8V
1
10
100
1000
LOAD CURRENT (mA)
Maxim Integrated │ 6
MAX8739
TFT, LCD, DC-DC Converter with
Operational Amplifiers
Typical Operating Characteristics (continued)
(Circuit of Figure 1, VIN = 2.5V, VMAIN = 8V, FREQ = IN, TA = +25°C, unless otherwise noted.)
20
NOT SWITCHING
10
2
3
4
5
SWITCHING
26
24
NOT SWITCHING
22
20
6
1400
-50
-20
10
40
70
FREQ = IN
1200
1000
800
FREQ = GND
600
400
100
MAX8739toc06
28
1
2
3
4
5
TEMPERATURE (°C)
INPUT VOLTAGE (V)
STEP-UP REGULATOR SOFT-START
(HEAVY LOAD)
STEP-UP REGULATOR
LOAD-TRANSIENT RESPONSE
STEP-UP REGULATOR PULSED
LOAD-TRANSIENT RESPONSE
A
0V
6
MAX8739 toc09
SUPPLY VOLTAGE (V)
MAX8739toc08
1
MAX8739 toc07
0
VIN = 3.3V
SWITCHING FREQUENCY (kHz)
30
SWITCHING FREQUENCY
vs. INPUT VOLTAGE
MAX8739toc05
MAX8739 toc04
SWITCHING
40
30
IN SUPPLY CURRENT (µA)
50
IN SUPPLY CURRENT (µA)
IN SUPPLY CURRENT
vs. TEMPERATURE
IN SUPPLY CURRENT
vs. SUPPLY VOLTAGE
0V
A
A
0V
0V
B
B
C
0A
0A
OA
C
C
B
OA
2ms/div
A: VIN, 2V/div
B: VMAIN, 5V/div
C: INDUCTOR CURRENT, 1A/div
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20µs/div
A: VMAIN, AC-COUPLED, 200mV/div
B: INDUCTOR CURRENT, 500mA/div
C: LOAD CURRENT, 500mA/div
OA
20µs/div
A: VMAIN, AC-COUPLED, 200mV/div
B: INDUCTOR CURRENT, 500mA/div
C: LOAD CURRENT, 500mA/div
Maxim Integrated │ 7
MAX8739
TFT, LCD, DC-DC Converter with
Operational Amplifiers
Typical Operating Characteristics (continued)
(Circuit of Figure 1, VIN = 2.5V, VMAIN = 8V, FREQ = IN, TA = +25°C, unless otherwise noted.)
SUP SUPPLY CURRENT
vs. SUP VOLTAGE
10
B
C
0V
D
C
53ms
E
OA
SUP SUPPLY CURRENT
vs. TEMPERATURE
NOT SWITCHING
10
40
TEMPERATURE (°C)
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4
6
8
10
12
OPERATIONAL-AMPLIFIER RAIL-TO-RAIL
INPUT/OUTPUT
BUFFER CONFIGURATION
0V
-2
-4
RL = 10kΩ
CL = 1000pF
AV = 1
VSUP = 8V
-8
-20
NOT SWITCHING
2
A
-6
2
-50
4
0
6
0
BUFFER CONFIGURATION
2
SWITCHING
4
OPERATIONAL-AMPLIFIER
FREQUENCY RESPONSE
MAX8739 toc14
8
4
MAX8739 toc13
VSUP = 8V
VIN = 3.3V
GAIN (dB)
SUP SUPPLY CURRENT (mA)
10
6
SUP VOLTAGE (V)
A: VLDO, 5V/div
B: VMAIN, 5V/div
C: VSRC, 20V/div
D: VGON, 20V/div
E: VGOFF, 5V/div
A: VIN, 2V/div
B: VMAIN, 5V/div
C: INDUCTOR CURRENT, 2A/div
8
0
2ms/div
10ms/div
SWITCHING
A
B
0V
MAX8739toc12
A
SUP CURRENT (mA)
MAX8739toc11
MAX8739toc10
POWER-UP SEQUENCE
MAX8739 toc15
TIMER DELAY LATCH
RESPONSE TO OVERLOAD
70
100
-10
100k
B
0A
1M
FREQUENCY (Hz)
10M
10µs/div
A: BUFFER INPUT, 5V/div
B: BUFFER OUTPUT, 5V/div
Maxim Integrated │ 8
MAX8739
TFT, LCD, DC-DC Converter with
Operational Amplifiers
Typical Operating Characteristics (continued)
(Circuit of Figure 1, VIN = 2.5V, VMAIN = 8V, FREQ = IN, TA = +25°C, unless otherwise noted.)
MAX8739 toc16
MAX8739 toc17
OPERATIONAL-AMPLIFIER
LARGE-SIGNAL STEP RESPONSE
OPERATIONAL-AMPLIFIER
LOAD TRANSIENT RESPONSE
A
A
0V
0V
B
B
0A
0V
1µs/div
1µs/div
A: INPUT VOLTAGE, 5V/div
B: OUTPUT VOLTAGE, 5V/div
A: OUTPUT VOLTAGE, AC-COUPLED, 2V/div
B: OUTPUT CURRENT, 50mA/div
OPERATIONAL-AMPLIFIER
SMALL-SIGNAL STEP RESPONSE
A
MAX8739toc19
MAX8739toc18
SWITCH CONTROL FUNCTION
RDRN = 5kΩ
CGON = 1.5nF
A
0V
0V
B
B
0V
0V
20µs/div
4µs/div
A: INPUT VOLTAGE, AC-COUPLED 50mV/div
B: OUTPUT VOLTAGE, AC-COUPLED 50mV/div
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A: VGON, 10V/div
B: VCTL, 2V/div
Maxim Integrated │ 9
MAX8739
TFT, LCD, DC-DC Converter with
Operational Amplifiers
Pin Description
PIN
NAME
1
COM
Internal High-Voltage MOSFET Switch Common Terminal
2
SRC
Switch Input. Source of the internal high-voltage, p-channel MOSFET. Bypass SRC to PGND with a
minimum of 0.1µF close to the pins.
3
LDO
Internal 5V Linear Regulator Output. This regulator powers all internal circuitry except OUT1 and OUT2
operational amplifiers. Bypass LDO to AGND with a 0.22µF or greater ceramic capacitor.
4
PGND
Power Ground. PGND is the source of the step-up regulator’s n-channel power MOSFET. Connect PGND
to the input capacitor ground terminals through a short, wide PC board trace. Connect PGND to analog
ground (AGND) underneath the IC.
5
AGND
Analog Ground. Connect AGND to power ground (PGND) underneath the IC.
6
POS1
Operational Amplifier 1 Noninverting Input
7
NEG1
Operational Amplifier 1 Inverting Input
8
OUT1
Operational Amplifier 1 Output
9
OUT2
Operational Amplifier 2 Output
10
NEG2
Operational Amplifier 2 Inverting Input
11
POS2
Operational Amplifier 2 Noninverting Input
12
SUP
13
LX
n-Channel Power MOSFET Drain and Switching Node. Connect the inductor and the catch diode to LX
and minimize the trace area for lowest EMI.
14
IN
Supply Voltage. IN can range from 1.8V to 5.5V.
15
FREQ
16
FB
17
COMP
18
DEL
High-Voltage Switch-Delay Input. Connect a capacitor from DEL to AGND to set the high-voltage switch
startup delay. A 5µA current source charges CDEL. The switches between SRC, COM, and DRN are
disabled during the delay period.
19
CTL
High-Voltage Switch-Control Input. When CTL is high, the high-voltage switch between COM and SRC
is on and the high-voltage switches between COM and DRN are off. When CTL is low, the high-voltage
switch between COM and SRC is off and the high-voltage switches between COM and DRN are on. CTL
is inhibited by the undervoltage lockout and when VDEL is less than 1.24V.
20
DRN
Switch Input. Drain of the internal, high-voltage, back-to-back p-channel MOSFETs connected to COM.
—
EP
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FUNCTION
Operational-Amplifier Supply Input. SUP is the positive supply rail for the OUT1 and OUT2 amplifiers.
SUP is also the supply input of the internal 5V linear regulator. Connect SUP to the main step-up regulator
output and bypass SUP to AGND with a 0.1µF capacitor.
Oscillator Frequency-Select Input. Pull FREQ low or leave it unconnected for 600kHz operation. Connect
FREQ to IN for 1.2MHz operation. This input has a 5µA pulldown.
Step-Up Regulator Feedback Input. Regulates to 1.24V (nominal). Connect a resistive voltage-divider from
the output (VMAIN) to FB to analog ground (AGND). Place the divider within 5mm of FB.
Step-Up Regulator Error-Amplifier Compensation Point. Connect a series resistor and capacitor from
COMP to AGND. See the Loop Compensation section for component selection guidelines.
Exposed Pad
Maxim Integrated │ 10
MAX8739
TFT, LCD, DC-DC Converter with
Operational Amplifiers
Typical Application Circuit
voltage range for the IC is from +1.8V to +5.5V, but the
Figure 1 circuit is designed to run from 1.8V to 2.7V. Table
1 lists the key recommended components and Table 2
lists the contact information of the component suppliers.
The MAX8739 typical application circuit (Figure 1) generates a +8V source-driver supply and approximately +22V
and -7V gate-driver supplies for TFT displays. The input
C15
0.1µF
VGOFF
-7V/20mA
D2
C13
0.1µF
VIN
+1.8V TO +2.7V
C1
10µF
6.3V
C4
1µF
R3
100kΩ
C5
220pF
C6
33pF
C16
0.1µF
L1
3.0µH
R4
10Ω
100kΩ
C14
0.1µF
D4
D1
LX
IN
FB
MAX8739
FREQ
AGND
COMP
PGND
C17
0.1µF
D3
R2
30.9kΩ
1%
C10
0.1µF
OUT1
C7
1µF
C8
0.033µF
FROM TCON
C3
4.7µF
10V
C2
4.7µF
10V
R1
169kΩ
1%
VMAIN
+8V/250mA
SUP
NEG1
TO VCOM
BACKPLANE
C18
0.1µF
NEG2
POS1
OUT2
POS2
C11
0.1µF
LDO
DEL
C12
0.1µF
R5*
R7*
R6*
R8*
SRC
R9
5kΩ
DRN
CTL
COM
VGON
+22V/10mA
*THE RATIO OF THE VOLTAGE DIVIDER DEPENDS ON THE EXACT APPLICATION REQUIREMENTS.
USE RESISTORS IN THE 100kΩ AND 500kΩ RANGE.
Figure 1. Typical Application Circuit
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Maxim Integrated │ 11
MAX8739
TFT, LCD, DC-DC Converter with
Operational Amplifiers
VIN
LX
MAX8739
IN
PGND
LDO
LINEAR
REGULATOR
AND BOOTSTRAP
FREQ
STEP-UP
REGULATOR
CONTROLLER
FB
COMP
NEG1
SRC
OUT1
DRN
POS1
NEG1
COM
SWITCH
CONTROL
OUT2
CTL
DEL
POS2
AGND
Figure 2. Functional Diagram
Table 1. Key Components List
DESIGNATION
DESCRIPTION
C1
10µF, 6.3V X5R ceramic capacitor (1206)
TDK C3216X5ROJ106M
C2, C3
4.7µF, 10V X5R ceramic capacitors (1206)
TDK C3216X5R1A475M
D1
D2, D3, D4
L1
3A, 30V Schottky diode (M-flat)
Toshiba CMS02
200mA, 100V, dual, ultra-fast diodes
(SOT23)
Fairchild MMBD4148SE
3.0µH, 2.3A inductor
Sumida CDRH6D12-3R0
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Detailed Description
The MAX8739 contains a high-performance, step-up
switching regulator, two high-current operational amplifiers, and startup timing and level-shifting functionality
useful for active-matrix TFT LCDs. Figure 2 shows the
MAX8739 functional diagram.
Main Step-Up Regulator
The main step-up regulator employs a current-mode,
fixed-frequency PWM architecture to maximize loop
bandwidth and provide fast transient response to pulsed
loads found in source drivers of TFT LCD panels. The
high-switching frequency (600kHz/1.2MHz) allows the
use of low-profile inductors and ceramic capacitors to
minimize the thickness of LCD panel designs. The integrated, high-efficiency MOSFET and the IC’s built-in
digital soft-start functions reduce the number of external
components required while controlling inrush current. The
output voltage can be set from VIN to 13V with an external
resistive voltage-divider.
Maxim Integrated │ 12
MAX8739
TFT, LCD, DC-DC Converter with
Operational Amplifiers
Table 2. Component Suppliers
SUPPLIER
PHONE
FAX
Fairchild
408-822-2000
408-822-2102
www.fairchildsemi.com
Sumida
847-545-6700
847-545-6720
www.sumida.com
TDK
847-803-6100
847-390-4405
www.component.tdk.com
Toshiba
949-455-2000
949-859-3963
www.toshiba.com/taec
The regulator controls the output voltage and the power
delivered to the output by modulating the duty cycle (D) of
the internal power MOSFET in each switching cycle. The
duty cycle of the MOSFET is approximated by:
WEBSITE
On the rising edge of the internal clock, the controller
sets a flip-flop, turning on the n-channel MOSFET and
applying the input voltage across the inductor. The current
through the inductor ramps up linearly, storing energy in
its magnetic field. Once the sum of the current-feedback
signal and the slope compensation exceed the COMP
voltage, the controller resets the flip-flop and turns off
the MOSFET. Since the inductor current is continuous,
a transverse potential develops across the inductor that
turns on the diode (D1). The voltage across the inductor
then becomes the difference between the output voltage
and the input voltage. This discharge condition forces the
current through the inductor to ramp back down, transferring the energy stored in the magnetic field to the output
capacitor and the load. The MOSFET remains off for the
rest of the clock cycle.
Operational Amplifiers
The MAX8739 has two operational amplifiers that are
typically used to drive the LCD backplane (VCOM) and/
or the gamma-correction-divider string. The operational
amplifiers feature ±150mA output short-circuit current,
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LOGIC AND
DRIVER
PGND
V
− VIN
D ≈ MAIN
VMAIN
Figure 3 shows the block diagram of the step-up regulator.
An error amplifier compares the signal at FB to 1.24V and
changes the COMP output. The voltage at COMP determines the current trip point each time the internal MOSFET
turns on. As the load varies, the error amplifier sources or
sinks current to the COMP output accordingly to produce
the inductor peak current necessary to service the load. To
maintain stability at high duty cycles, a slope compensation
signal is summed with the current-sense signal.
LX
CLOCK
ILIM
COMPARATOR
SOFTSTART
ILIMIT
SS
SLOPE COMP
OSCILLATOR
PWM
COMPARATOR
∑
CURRENT
SENSE
FAULT
COMPARATOR
TO FAULT LOGIC
1.0V
ERROR AMP
FB
1.24V
COMP
FREQ
Figure 3. Step-Up Regulator Block Diagram
7.5V/µs slew rate, and 12MHz bandwidth. The rail-to-rail
input and output capability maximize system flexibility.
Short-Circuit Current Limit
The operational amplifiers limit short-circuit current to
approximately ±150mA if the output is directly shorted to
SUP or to AGND. If the short-circuit condition persists,
the junction temperature of the IC rises until it reaches
the thermal-shutdown threshold (+160°C typ). Once
the junction temperature reaches the thermal-shutdown
threshold, an internal thermal sensor immediately sets the
thermal fault latch, shutting off all the IC’s outputs. The
device remains inactive until the input voltage is cycled.
Driving Pure Capacitive Loads
The operational amplifiers are typically used to drive the
LCD backplane (VCOM) or the gamma-correction-divider
string. The LCD backplane consists of a distributed series
Maxim Integrated │ 13
MAX8739
TFT, LCD, DC-DC Converter with
Operational Amplifiers
capacitance and resistance, a load that can be easily driven by the operational amplifier. However, if the operational
amplifier is used in an application with a pure capacitive
load, steps must be taken to ensure stable operation.
As the operational amplifier’s capacitive load increases,
the amplifier’s bandwidth decreases and gain peaking
increases. A 5Ω to 50Ω resistor placed between OUT_
and the capacitive load reduces peaking but also reduces
the gain. An alternative method of reducing peaking is to
place a series RC network (snubber) in parallel with the
capacitive load. The RC network does not continuously
load the output or reduce the gain. Typical values of the
resistor are between 100Ω and 200Ω and the typical
value of the capacitor is 10pF.
Switch Control and Delay
A capacitor CDEL (C8 in Figure 1), from DEL to AGND
selects the switch-control block supply startup delay. After
the LDO voltage exceeds its undervoltage lockout threshold (2.7V typ) and the soft-start routine for each regulator
is complete, a 5µA current source charges CDEL. Once
the capacitor voltage exceeds VREF (1.25V typ), COM
can be connected to SRC or DRN through the internal
p-channel switches, depending upon the state of CTL.
Before startup and when IN is less than VUVLO, DEL is
internally connected to AGND to discharge CDEL. Select
CDEL to set the delay time using the following equation:
C DEL = DELAY_TIME x
5µA
1.25V
The switch-control input (CTL) is not activated until all
three of the following conditions are satisfied: the LDO
voltage exceeds its undervoltage lockout voltage, the
soft-start routine of all the regulators is complete, and
VDEL exceeds its turn-on threshold. Once activated and
if CTL is high, the 15Ω internal p-channel switch between
COM and SRC (Q1) turns on and the 30Ω p-channel
switch between DRN and COM (Q2) turns off. If CTL is
low, Q1 turns off and Q2 turns on.
LDO
5µA
2.7V
SRC
Q1
DLP
REF
COM
CTL
Q2
DRN
Figure 4. Switch Control
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Maxim Integrated │ 14
MAX8739
Undervoltage Lockout (UVLO)
The undervoltage lockout (UVLO) circuit compares the
input voltage at IN with the UVLO threshold (1.26V rising
and 1.1V falling) to ensure that the input voltage is high
enough for reliable operation. The 200mV (typ) hysteresis
prevents supply transients from causing a restart. Once
the input voltage exceeds the UVLO rising threshold,
startup begins. When the input voltage falls below the
UVLO falling threshold, the controller turns off the main
step-up regulator and the linear regulator outputs, disables the switch-control block, and the operational amplifier outputs are high impedance.
Linear Regulator (LDO)
The MAX8739 includes an internal 5V linear regulator.
SUP is the input of the linear regulator. The input voltage
range is between 4.5V and 13V. The output of the linear
regulator (LDO) is set to 5V (typ). The regulator powers
all the internal circuitry including the gate driver. Bypass
the LDO pin to AGND with a 0.22µF or greater ceramic
capacitor. SUP should be directly connected to the output of the step-up regulator. This feature significantly
improves the efficiency at low-input voltages.
Bootstrapping and Soft-Start
The MAX8739 features bootstrapping operation. In normal operation, the internal linear regulator supplies power
to the internal circuitry. The input of the linear regulator
(IN) should be directly connected to the output of the
step-up regulator. The MAX8739 is enabled when the
input voltage at SUP is above 1.3V (typ) and the fault
latch is not set. After being enabled, the regulator starts
open-loop switching to generate the supply voltage for
the linear regulator. The internal reference block turns
on when the LDO voltage exceeds 2.7V (typ). When the
reference voltage reaches regulation, the PWM controller
and the current-limit circuit are enabled, and the step-up
regulator enters soft-start. During soft-start, the main
step-up regulator directly limits the peak-inductor current,
allowing from zero up to the full current-limit value in eight
equal current steps (ILIM/8). The maximum load current
is available after the output voltage reaches regulation
(which terminates soft-start), or after the soft-start timer
expires in approximately 13ms. The soft-start routine
minimizes the inrush current and voltage overshoot and
ensures a well-defined startup behavior.
Fault Protection
During steady-state operation, the MAX8739 monitors the
FB voltage. If the FB voltage does not exceed 1V (typ),
the MAX8739 activates an internal fault timer. If there is a
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TFT, LCD, DC-DC Converter with
Operational Amplifiers
continuous fault for the fault-timer duration, the MAX8739
sets the fault latch, shutting down all the outputs. Once
the fault condition is removed, cycle the input voltage to
clear the fault latch and reactivate the device. The faultdetection circuit is disabled during the soft-start time.
The MAX8739 monitors the SUP voltage for undervoltage
and overvoltage conditions. If the SUP voltage is below
1.4V (max) or above 13.7V (typ), the MAX8739 disables
the gate driver of the step-up regulator and prevents the
internal MOSFET from switching. The SUP undervoltage
and overvoltage conditions do not set the fault latch.
Thermal-Overload Protection
The thermal-overload protection prevents excessive
power dissipation from overheating the device. When the
junction temperature exceeds TJ = +160°C, a thermal
sensor immediately activates the fault protection, which
shuts down the step-up regulator and the internal linear
regulator, allowing the device to cool down. Once the
device cools down by approximately 15°C, cycle the input
voltage (below the UVLO falling threshold) to clear the
fault latch and reactivate the device.
The thermal-overload protection protects the controller in
the event of fault conditions. For continuous operation, do
not exceed the absolute maximum junction temperature
rating of TJ = +150°C.
Design Procedure
Main Step-Up Regulator
Inductor Selection
The minimum inductance value, peak-current rating, and
series resistance are factors to consider when selecting the inductor. These factors influence the converter’s
efficiency, maximum output-load capability, transient
response time, and output-voltage ripple. Physical size
and cost are also important factors to be considered.
The maximum output current, input voltage, output voltage, and switching frequency determine the inductor
value. Very-high inductance values minimize the current ripple and therefore reduce the peak current, which
decreases core losses in the inductor and I2R losses in
the entire power path. However, large inductor values
also require more energy storage and more turns of
wire, which increase physical size and can increase I2R
losses in the inductor. Low-inductance values decrease
the physical size but increase the current ripple and peak
current. Finding the best inductor involves choosing the
best compromise between circuit efficiency, inductor size,
and cost.
Maxim Integrated │ 15
MAX8739
TFT, LCD, DC-DC Converter with
Operational Amplifiers
The equations used here include a constant LIR, which is
the ratio of the inductor peak-to-peak ripple current to the
average DC inductor current at the full load current. The
best trade-off between inductor size and circuit efficiency
for step-up regulators generally has an LIR between 0.3
and 0.5. However, depending on the AC characteristics of
the inductor core material and ratio of inductor resistance
to other power-path resistances, the best LIR can shift up
or down. If the inductor resistance is relatively high, more
ripple can be accepted to reduce the number of turns
required and increase the wire diameter. If the inductor
resistance is relatively low, increasing inductance to lower
the peak current can decrease losses throughout the
power path. If extremely thin, high-resistance inductors
are used, as is common for LCD panel applications, the
best LIR can increase to between 0.5 and 1.0.
good efficiency, choose an inductor with less than 0.1Ω
series resistance.
Considering the Typical Operating Circuit, the maximum
load current (IMAIN(MAX)) is 300mA, with an 8V output
and a typical input voltage of 2.5V. Choosing an LIR of 0.4
and estimating efficiency of 85% at this operating point:
2
2.5V
8V − 2.5V 0.85
L
=
× 0.3A × 1.2MHz × 0.4 ≈ 3.0µH
8V
Using the circuit’s minimum input voltage (2.2V) and estimating efficiency of 80% at that operating point:
=
IIN(DC,MAX)
0.3A × 8V
≈ 1.36A
2.2V × 0.8
The ripple current and the peak current are:
Once a physical inductor is chosen, higher and lower
values of the inductor should be evaluated for efficiency
2.2V × (8V − 2.2V)
improvements in typical operating regions.
=
IRIPPLE
≈ 0.44A
3.0µH × 8V × 1.2MHz
Calculate the approximate inductor value using the
0.44A
typical input voltage (VIN), the maximum output curIPEAK =1.36A +
≈ 1.58A
2
rent (IMAIN(MAX)), the expected efficiency (ηTYP) taken
from an appropriate curve in the Typical Operating
Output-Capacitor Selection
Characteristics, and an estimate of LIR based on the
The total output-voltage ripple has two components: the
above discussion:
capacitive ripple caused by the charging and discharging
2
η
VIN
VMAIN − VIN
× TYP
L=
×
V
I
f
LIR
×
MAIN
MAIN(MAX) OSC
Choose an available inductor value from an appropriate
inductor family. Calculate the maximum DC input current
at the minimum input voltage VIN(MIN) using conservation of energy and the expected efficiency at that operating point (ηMIN) taken from an appropriate curve in the
Typical Operating Characteristics:
IIN(DC,MAX) =
IMAIN(MAX) × VMAIN
VIN(MIN) × η MIN
Calculate the ripple current at that operating point and the
peak current required for the inductor:
IRIPPLE =
VIN(MIN) × (VMAIN − VIN(MIN) )
L × VMAIN × f OSC
I
=
IPEAK IIN(DC,MAX) + RIPPLE
2
The inductor’s saturation current rating and the MAX8739’s
LX current limit (ILIM) should exceed IPEAK and the inductor’s DC current rating should exceed IIN(DC,MAX). For
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of the output capacitance, and the ohmic ripple due to the
capacitor’s equivalent series resistance (ESR):
VRIPPLE = VRIPPLE(C) + VRIPPLE(ESR)
V
I
− VIN
VRIPPLE(C) ≈ MAIN × MAIN
C OUT VMAIN × f SW
and:
VRIPPLE(ESR) ≈ IPEAK x RESR
where IPEAK is the peak inductor current (see
the Inductor Selection section). For ceramic capacitors, the output voltage ripple is typically dominated by
VRIPPLE(C). The voltage rating and temperature characteristics of the output capacitor must also be considered.
Input-Capacitor Selection
The input capacitor (CIN) reduces the current peaks
drawn from the input supply and reduces noise injection into the IC. A 10µF ceramic capacitor is used in the
Typical Application Circuit (Figure 1) because of the high
source impedance seen in typical lab setups. Actual applications usually have much lower source impedance since
the step-up regulator often runs directly from the output of
another regulated supply. Typically, CIN can be reduced
Maxim Integrated │ 16
MAX8739
TFT, LCD, DC-DC Converter with
Operational Amplifiers
below the values used in the Typical Application Circuit.
Ensure a low noise supply at IN by using adequate CIN.
Alternatively, greater voltage variation can be tolerated on
CIN if IN is decoupled from CIN using an RC lowpass filter
(see Figure 1).
Rectifier Diode
The MAX8739’s high switching frequency demands a
high-speed rectifier. Schottky diodes are recommended
for most applications because of their fast recovery time
and low forward voltage. In general, a 3A Schottky diode
complements the internal MOSFET well.
Output-Voltage Selection
The output voltage of the main step-up regulator can be
adjusted by connecting a resistive voltage-divider from
the output (VMAIN) to AGND with the center tap connected to FB (see Figure 1). Select R2 in the 10kΩ to 50kΩ
range. Calculate R1 with the following equation:
V
R1
= R2 × MAIN − 1
VFB
where VFB, the step-up regulator’s feedback set point, is
1.236V. Place R1 and R2 close to the IC.
Loop Compensation
Choose RCOMP to set the high-frequency integrator gain
for fast transient response. Choose CCOMP to set the
integrator zero to maintain loop stability.
For low-ESR output capacitors, use the following equations to obtain stable performance and good transient
response:
R COMP ≈
315 × VIN × VOUT × C OUT
L × IMAIN(MAX)
C COMP ≈
VOUT × C OUT
10 × IMAIN(MAX) × R COMP
To further optimize transient response, vary RCOMP in
20% steps and CCOMP in 50% steps while observing
transient response waveforms.
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Applications Information
Power Dissipation
An IC’s maximum power dissipation depends on the thermal resistance from the die to the ambient environment
and the ambient temperature. The thermal resistance
depends on the IC package, PC board copper area, other
thermal mass, and airflow.
The MAX8739, with its exposed backside pad soldered to
1in2 of PC board copper, can dissipate about 1.7W into
+70°C still air. More PC board copper, cooler ambient air,
and more airflow increase the possible dissipation, while
less copper or warmer air decreases the IC’s dissipation
capability. The major components of power dissipation
are the power dissipated in the step-up regulator and the
power dissipated by the operational amplifiers.
Step-Up Regulator
The largest portions of power dissipation in the step-up
regulator are the internal MOSFET, inductor, and the
output diode. If the step-up regulator has 90% efficiency,
about 3% to 5% of the power is lost in the internal
MOSFET, about 3% to 4% in the inductor, and about 1%
in the output diode. The remaining 1% to 3% is distributed
among the input and output capacitors and the PC board
traces. If the input power is about 5W, the power lost in
the internal MOSFET is about 150mW to 250mW.
Operational Amplifier
The power dissipated in the operational amplifiers
depends on their output current, the output voltage, and
the supply voltage:
PDSOURCE = IOUT_SOURCE x (VSUP - VOUT_)
PDSINK = IOUT_(SINK) x VOUT_
where IOUT_(SOURCE) is the output current sourced by
the operational amplifier, and IOUT_(SINK) is the output
current that the operational amplifier sinks.
In a typical case where the supply voltage is 10V and
the output voltage is 5V with an output source current of
30mA, the power dissipated is 150mW.
Maxim Integrated │ 17
3) Place the feedback-voltage-divider resistors as close
to the feedback pin as possible. The divider’s center
trace should be kept short. Placing the resistors far
away causes the FB traces to become antennas that
can pick up switching noise. Care should be taken
to avoid running any feedback trace near LX or the
switching nodes in the charge pumps.
4) Place IN pin and LDO pin bypass capacitors as close
to the device as possible. The ground connections
of the IN and LDO bypass capacitors should be connected directly to the AGND pin with a wide trace.
5) Minimize the length and maximize the width of the
traces between the output capacitors and the load for
best transient responses.
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IN
LX
SUP
POS2
13
12
11
TOP VIEW
14
Pin Configuration
FB
16
10
NEG2
COMP
17
9
OUT2
DEL
18
8
OUT1
CTL
19
7
NEG1
DRN
20
6
POS1
4
5
AGND
3
LDO
PGND
2
MAX8739
SRC
2) Create a power-ground island (PGND) consisting of
the input and output capacitor grounds, PGND pin,
and any charge-pump components. Connect all these
together with short, wide traces or a small ground
plane. Maximizing the width of the power-ground
traces improves efficiency and reduces output voltage ripple and noise spikes. Create an analog ground
plane (AGND) consisting of the AGND pin, all the
feedback-divider ground connections, the operationalamplifier-divider ground connections, the COMP and
DEL capacitor ground connections, the SUP and
LDO bypass capacitor ground connections, and the
device’s exposed backside pad. Connect the AGND
and PGND islands by connecting the PGND pin
directly to the exposed backside pad. Make no other
connections between these separate ground planes.
Refer to the MAX8739 evaluation kit for an example of
proper board layout.
FREQ
1) Minimize the area of high-current loops by placing the
inductor, output diode, and output capacitors near the
input capacitors and near the LX and PGND pins. The
high-current input loop goes from the positive terminal
of the input capacitor to the inductor, to the IC’s LX
pin, out of PGND, and to the input capacitor’s negative terminal. The high-current output loop is from the
positive terminal of the input capacitor to the inductor, to the output diode (D1), to the positive terminal
of the output capacitors, reconnecting between the
output capacitor and input capacitor ground terminals.
Connect these loop components with short, wide connections. Avoid using vias in the high-current paths.
If vias are unavoidable, use many vias in parallel to
reduce resistance and inductance.
15
Careful PC board layout is important for proper operation.
Use the following guidelines for good PC board layout:
6) Minimize the size of the LX node while keeping it wide
and short. Keep the LX node away from the feedback
node and analog ground. Use DC traces as shield if
necessary.
1
PC Board Layout and Grounding
TFT, LCD, DC-DC Converter with
Operational Amplifiers
COM
MAX8739
TQFN
5mm x 5mm
Chip Information
Transistor Count: 4396
PROCESS: BiCMOS
Package Information
For the latest package outline information and land patterns
(footprints), go to www.maximintegrated.com/packages. Note
that a “+”, “#”, or “-” in the package code indicates RoHS status
only. Package drawings may show a different suffix character, but
the drawing pertains to the package regardless of RoHS status.
PACKAGE
TYPE
PACKAGE
CODE
20 TQFN
T2055+4
OUTLINE LAND PATTERN
NO.
NO.
21-0140
90-0009
Maxim Integrated │ 18
MAX8739
TFT, LCD, DC-DC Converter with
Operational Amplifiers
Revision History
REVISION
NUMBER
REVISION
DATE
PAGES
CHANGED
0
1/06
Initial release
1
7/14
No /V OPNs; removed automotive reference from Applications section; updated
Package Information section, including package code
DESCRIPTION
—
1, 19–21
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses
are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits)
shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
© 2014 Maxim Integrated Products, Inc. │ 19
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