LT3014B
20mA, 3V to 80V
Low Dropout Micropower
Linear Regulator
FEATURES
DESCRIPTION
Wide Input Voltage Range: 3V to 80V
Low Quiescent Current: 7µA
Low Dropout Voltage: 350mV
Output Current: 20mA
LT3014BHV Survives 100V Transients (2ms)
No Protection Diodes Needed
Adjustable Output from 1.22V to 60V
Stable with 0.47µF Output Capacitor
Stable with Aluminum, Tantalum or Ceramic
Capacitors
n Reverse-Battery Protection
n No Reverse Current Flow from Output
n Thermal Limiting
n Available in 5-Lead ThinSOTTM and
8-Lead DFN Packages
The LT®3014B is a high voltage, micropower low dropoutlinear regulator. The device is capable of supplying
20mA of output current with a dropout voltage of 350mV.
Designed for use in battery-powered or high voltage systems, the low quiescent current (7µA operating) makes
the LT3014B an ideal choice. Quiescent current is also
well controlled in dropout.
n
n
n
n
n
n
n
n
n
The device is available as an adjustable device with a 1.22V
reference voltage. The LT3014B regulator is available in
the 5-lead ThinSOT and 8-lead DFN packages.
APPLICATIONS
n
n
n
n
Other features of the LT3014B include the ability to operate
with very small output capacitors. The regulators are stable
with only 0.47µF on the output while most older devices
require between 10µF and 100µF for stability. Small ceramic
capacitors can be used without the necessary addition of
ESR as is common with other regulators. Internal protection circuitry includes reverse-battery protection, current
limiting, thermal limiting and reverse current protection.
Low Current High Voltage Regulators
Regulator for Battery-Powered Systems
Telecom Applications
Automotive Applications
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
ThinSOT is a trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Protected by U.S. Patents including 6118263, 6144250.
TYPICAL APPLICATION
Dropout Voltage
5V Supply
VIN
5.4V TO
80V
1µF
OUT
LT3014B
3.92M
ADJ
GND
1.27M
3014B TA01
VOUT
5V
20mA
0.47µF
350
DROPOUT VOLTAGE (mV)
IN
400
300
250
200
150
100
50
0
0
2
4
6 8 10 12 14 16 18 20
OUTPUT CURRENT (mA)
3014B TA02
3014bfb
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1
LT3014B
ABSOLUTE MAXIMUM RATINGS
(Note 1)
IN Pin Voltage, Operating.........................................±80V
Transient (2ms Survival, LT3014BHV)................... +100V
OUT Pin Voltage.......................................................±60V
IN to OUT Differential Voltage................................. ±80V
ADJ Pin Voltage.........................................................±7V
Output Short-Circuit Duration........................... Indefinite
Storage Temperature Range
ThinSOT Package............................–65°C to 150°C
DFN Package...................................–65°C to 125°C
Operating Junction Temperature Range (Notes 3, 9, 10)
E-Grade, I-Grade.............................–40°C to 125°C
MP-Grade........................................–55°C to 125°C
Lead Temperature (Soldering, 10 sec)
SOT-23 Package.............................................300°C
PIN CONFIGURATION
TOP VIEW
TOP VIEW
IN 1
5 OUT
GND 2
NC 3
4 ADJ
S5 PACKAGE
5-LEAD PLASTIC SOT-23
TJMAX = 125°C, θJA = 150°C/ W
θJC = 25°C/W MEASURED AT PIN 2
SEE APPLICATIONS INFORMATION SECTION
OUT
1
8
IN
ADJ
2
7
NC
NC
3
6
NC
GND
4
5
NC
9
DD PACKAGE
8-LEAD (3mm × 3mm) PLASTIC DFN
TJMAX = 125°C, θJA = 40°C/W
θJC = 10°C/W MEASURED AT PIN 9
EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB
3014bfb
2
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LT3014B
ORDER INFORMATION
LEAD FREE FINISH
TAPE AND REEL
PART MARKING*
PACKAGE DESCRIPTION
TEMPERATURE RANGE
LT3014BES5#PBF
LT3014BES5#TRPBF
LTCHK
5-Lead Plastic SOT-23
–40°C to 125°C
LT3014BIS5#PBF
LT3014BIS5#TRPBF
LTCHK
5-Lead Plastic SOT-23
–40°C to 125°C
LT3014BMPS5#PBF
LT3014BMPS5#TRPBF
LTCHK
5-Lead Plastic SOT-23
–55°C to 125°C
LT3014BHVES5#PBF
LT3014BHVES5#TRPBF
LTCHN
5-Lead Plastic SOT-23
–40°C to 125°C
LT3014BHVIS5#PBF
LT3014BHVIS5#TRPBF
LTCHN
5-Lead Plastic SOT-23
–40°C to 125°C
LT3014BEDD#PBF
LT3014BEDD#TRPBF
LCHM
8-Lead (3mm × 3mm) Plastic DFN
–40°C to 125°C
LT3014BIDD#PBF
LT3014BIDD#TRPBF
LCHM
8-Lead (3mm × 3mm) Plastic DFN
–40°C to 125°C
LT3014BHVEDD#PBF
LT3014BHVEDD#TRPBF
LCHP
8-Lead (3mm × 3mm) Plastic DFN
–40°C to 125°C
LT3014BHVIDD#PBF
LT3014BHVIDD#TRPBF
LCHP
8-Lead (3mm × 3mm) Plastic DFN
–40°C to 125°C
LEAD BASED FINISH
TAPE AND REEL
PART MARKING*
PACKAGE DESCRIPTION
TEMPERATURE RANGE
LT3014BES5
LT3014BES5#TR
LTCHK
5-Lead Plastic SOT-23
–40°C to 125°C
LT3014BIS5
LT3014BIS5#TR
LTCHK
5-Lead Plastic SOT-23
–40°C to 125°C
LT3014BMPS5
LT3014BMPS5#TR
LTCHK
5-Lead Plastic SOT-23
–55°C to 125°C
LT3014BHVES5
LT3014BHVES5#TR
LTCHN
5-Lead Plastic SOT-23
–40°C to 125°C
LT3014BHVIS5
LT3014BHVIS5#TR
LTCHN
5-Lead Plastic SOT-23
–40°C to 125°C
LT3014BEDD
LT3014BEDD#TR
LCHM
8-Lead (3mm × 3mm) Plastic DFN
–40°C to 125°C
LT3014BIDD
LT3014BIDD#TR
LCHM
8-Lead (3mm × 3mm) Plastic DFN
–40°C to 125°C
LT3014BHVEDD
LT3014BHVEDD#TR
LCHP
8-Lead (3mm × 3mm) Plastic DFN
–40°C to 125°C
LT3014BHVIDD
LT3014BHVIDD#TR
LCHP
8-Lead (3mm × 3mm) Plastic DFN
–40°C to 125°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
This product is only offered in trays. For more information go to: http://www.linear.com/packaging/
3014bfb
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3
LT3014B
ELECTRICAL
CHARACTERISTICS
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TJ = 25°C.
SYMBOL
CONDITIONS
Minimum Input Voltage
ILOAD = 20mA
ADJ Pin Voltage
(Notes 2, 3)
VIN = 3.3V, ILOAD = 100µA
3.3V < VIN < 80V, 100µA < ILOAD < 20mA
l
Line Regulation
DVIN = 3.3V to 80V, ILOAD = 100µA (Note 2)
l
Load Regulation
VIN = 3.3V, DILOAD = 100µA to 20mA (Note 2)
VIN = 3.3V, DILOAD = 100µA to 20mA
l
ILOAD = 100µA
ILOAD = 100µA
l
ILOAD = 1mA
ILOAD = 1mA
l
ILOAD = 10mA
ILOAD = 10mA
l
ILOAD = 20mA
ILOAD = 20mA
l
ILOAD = 0mA
ILOAD = 100µA
ILOAD = 1mA
ILOAD = 10mA
ILOAD = 20mA
l
l
l
l
l
Dropout Voltage
VIN = VOUT(NOMINAL) (Notes 4, 5)
GND Pin Current
VIN = VOUT(NOMINAL) (Notes 4, 6)
MIN
TYP
3
3.3
V
1.200
1.180
1.220
1.220
1.240
1.260
V
V
l
Output Voltage Noise
COUT = 0.47µF, ILOAD = 20mA, BW = 10Hz to 100kHz
ADJ Pin Bias Current
(Note 7)
Ripple Rejection
VIN = 7V (Avg), VRIPPLE = 0.5VP-P , fRIPPLE = 120Hz, ILOAD = 20mA
Current Limit
VIN = 7V, VOUT = 0V
VIN = 3.3V, DVOUT = –0.1V (Note 2)
l
Input Reverse Leakage Current
VIN = –80V, VOUT = 0V
l
Reverse Output Current (Note 8)
VOUT = 1.22V, VIN < 1.22V (Note 2)
1
10
mV
25
40
mV
mV
120
180
250
mV
mV
200
270
360
mV
mV
300
350
450
mV
mV
350
410
570
mV
mV
7
12
40
250
650
20
30
100
450
1000
µA
µA
µA
µA
µA
115
60
25
UNITS
13
4
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: The LT3014B is tested and specified for these conditions with the
ADJ pin connected to the OUT pin.
Note 3: Operating conditions are limited by maximum junction
temperature. The regulated output voltage specification will not apply
for all possible combinations of input voltage and output current. When
operating at maximum input voltage, the output current range must be
limited. When operating at maximum output current, the input voltage
range must be limited.
Note 4: To satisfy requirements for minimum input voltage, the LT3014B
is tested and specified for these conditions with an external resistor
divider (249k bottom, 392k top) for an output voltage of 3.3V. The external
resistor divider adds a 5µA DC load on the output.
Note 5: Dropout voltage is the minimum input to output voltage differential
needed to maintain regulation at a specified output current. In dropout, the
output voltage is equal to (VIN – VDROPOUT).
MAX
µVRMS
10
nA
70
dB
70
mA
mA
2
6
mA
4
µA
Note 6: GND pin current is tested with VIN = VOUT (nominal) and a current
source load. This means the device is tested while operating in its dropout
region. This is the worst-case GND pin current. The GND pin current
decreases slightly at higher input voltages.
Note 7: ADJ pin bias current flows into the ADJ pin.
Note 8: Reverse output current is tested with the IN pin grounded and the
OUT pin forced to the rated output voltage. This current flows into the OUT
pin and out of the GND pin.
Note 9: The LT3014B is tested and specified under pulse load conditions
such that TJ @ TA. The LT3014BE is 100% tested at TA = 25°C.
Performance at –40°C to 125°C is assured by design, characterization,
and statistical process controls. The LT3014BI is guaranteed over the full
–40°C to 125°C operating junction temperature range. The LT3014BMP is
100% tested and guaranteed over the –55°C to 125°C operating junction
temperature range.
Note 10: This IC includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed 125°C when overtemperature protection is active.
Continuous operation above the specified maximum operating junction
temperature may impair device reliability.
3014bfb
4
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LT3014B
TYPICAL PERFORMANCE CHARACTERISTICS
Guaranteed Dropout Voltage
600
450
500
TJ = 125°C
DROPOUT VOLTAGE (mV)
DROPOUT VOLTAGE (mV)
400
350
300
TJ = 25°C
250
200
150
100
500
= TEST POINTS
400
TJ ≤ 25°C
300
200
100
400
0
2
4
0
6 8 10 12 14 16 18 20
OUTPUT CURRENT (mA)
250
0
150
VIN = 6V
RL = ∞
IL = 0
2
4
4
2
75
50
25
TEMPERATURE (°C)
0
100
125
IL = 100µA
1.230
1.225
1.220
1.215
1.210
1.200
–50 –25
1000
75
50
25
TEMPERATURE (°C)
0
GND PIN CURRENT (µA)
GND PIN CURRENT (µA)
RL = 61Ω
IL = 20mA*
600
500
400
RL = 122Ω
IL = 10mA*
300
200
0
1
2
3 4 5 6 7
INPUT VOLTAGE (V)
9
10
3014B G07
8
6
4
0
1
2
3 4 5 6 7
INPUT VOLTAGE (V)
9
10
ADJ Pin Bias Current
14
12
700
600
500
400
300
0
8
3014B G06
GND Pin Current vs ILOAD
10
8
6
4
2
100
8
10
0
125
200
RL = 1.22k
IL = 1mA*
100
100
VIN = 3.3V
900 TJ = 25°C
= 1.22V
V
800 OUT
800
700
12
3014B G05
GND Pin Current
TJ = 25°C
900 *FOR VOUT = 1.22V
TJ = 25°C
14 RL = ∞
VOUT = 1.22V
2
3014B G04
1000
125
Quiescent Current
1.205
0
–50 –25
100
16
QUIESCENT CURRENT (µA)
ADJ PIN VOLTAGE (V)
6
50
25
0
75
TEMPERATURE (°C)
–25
3014B G03
ADJ PIN BIAS CURRENT (nA)
QUIESCENT CURRENT (µA)
8
0
0
–50
6 8 10 12 14 16 18 20
OUTPUT CURRENT (mA)
1.235
10
IL = 100µA
100
ADJ Pin Voltage
1.240
12
IL = 1mA
200
3014B G02
Quiescent Current
14
IL = 10mA
300
50
3014B G01
16
IL = 20mA
350
50
0
Dropout Voltage
450
TJ ≤ 125°C
DROPOUT VOLTAGE (mV)
Typical Dropout Voltage
500
0
2
4
6 8 10 12 14 16 18 20
OUTPUT CURRENT (mA)
3014B G08
0
–50
–25
0
50
75
25
TEMPERATURE (°C)
100
125
3014B G12
3014bfb
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5
LT3014B
TYPICAL PERFORMANCE CHARACTERISTICS
Current Limit
100
90
50
40
30
20
70
60
50
40
30
20
10
0
VIN = 7V
VOUT = 0V
80
60
CURRENT LIMIT (mA)
CURRENT LIMIT (mA)
VOUT = 0V
70 TJ = 25°C
Reverse Output Current
50
REVERSE OUTPUT CURRENT (µA)
Current Limit
80
10
0
2
4
–25
50
25
0
75
TEMPERATURE (°C)
Reverse Output Current
5
4
3
2
75
50
25
TEMPERATURE (°C)
0
100
64
62
60
–25
0.5
75
50
25
TEMPERATURE (°C)
0
100
125
40
–10
–15
–20
–25
–30
0
25
50
75
100
125
TEMPERATURE (°C)
3014B G19
COUT = 4.7µF
30
20
COUT = 0.47µF
100
1k
10k
FREQUENCY (Hz)
100k
1M
3014B G18
Output Noise Spectral Density
∆IL = 100µA TO 20mA
VOUT = 1.22V
–40
–50 –25
10
50
0
10
125
–35
100
9
VIN = 7V + 50mVRMS RIPPLE
IL = 20mA
10
OUTPUT NOISE SPECTRAL DENSITY (µV/√Hz)
–5
LOAD REGULATION (mV)
MINIMUM INPUT VOLTAGE (V)
ILOAD = 20mA
3.0
1.0
3 4 5 6 7 8
OUTPUT VOLTAGE (V)
60
Load Regulation
1.5
2
3014B G17
0
2.0
1
0
70
66
Minimum Input Voltage
25
75
0
50
TEMPERATURE (°C)
10
Input Ripple Rejection
VIN = 7V + 0.5VP-P
70 RIPPLE AT f = 120Hz
IL = 20mA
68
56
–50
125
2.5
CURRENT FLOWS
INTO OUTPUT PIN
15
80
3014B G16
0
–50 –25
20
3014B G15
58
1
–25
25
0
125
RIPPLE REJECTION (dB)
VIN = 0V
VOUT = VADJ = 1.22V
0
–50
30
Input Ripple Rejection
6
3.5
100
72
RIPPLE REJECTION (dB)
REVERSE OUTPUT CURRENT (µA)
7
35
3014B G14
3014B G13
8
ADJ PIN
ESD CLAMP
5
0
–50
6 8 10 12 14 16 18 20
INPUT VOLTAGE (V)
TJ = 25°C
45 VIN = 0V
= VADJ
V
40 OUT
3014B G20
10
COUT = 0.47µF
IL = 20mA
VOUT = 1.22V
1
0.1
0.01
10
100
1k
10k
FREQUENCY (Hz)
100k
3014B G21
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LT3014B
TYPICAL PERFORMANCE CHARACTERISTICS
Transient Response
VOUT
200µV/DIV
COUT = 0.47µF
IL = 20mA
VOUT = 1.22V
1ms/DIV
3014B G22
LOAD CURRENT (mA)
OUTPUT VOLTAGE
DEVIATION (V)
10Hz to 100kHz Output Noise
0.04
0.02
0
VIN = 7V
VOUT = 5V
CIN = COUT = 0.47µF CERAMIC
∆ILOAD = 1mA TO 5mA
–0.02
–0.04
6
4
2
0
0
200
600
400
TIME (µs)
800
1000
3014B G23
PIN FUNCTIONS
(SOT-23 Package/DD Package)
IN (Pin 1/Pin 8): Input. Power is supplied to the device
through the IN pin. A bypass capacitor is required on this
pin if the device is more than six inches away from the main
input filter capacitor. In general, the output impedance of
a battery rises with frequency, so it is advisable to include
a bypass capacitor in battery-powered circuits. A bypass
capacitor in the range of 0.1µF to 10µF is sufficient. The
LT3014B is designed to withstand reverse voltages on
the IN pin with respect to ground and the OUT pin. In the
case of a reversed input, which can happen if a battery is
plugged in backwards, the LT3014B will act as if there is
a diode in series with its input. There will be no reverse
current flow into the LT3014B and no reverse voltage
will appear at the load. The device will protect both itself
and the load.
GND (Pin 2/Pins 4, 9): Ground.
ADJ (Pin 4/Pin 2): Adjust. This is the input to the error
amplifier. This pin is internally clamped to ±7V. It has a bias
current of 4nA which flows into the pin (see curve of ADJ
Pin Bias Current vs Temperature in the Typical Performance
Characteristics). The ADJ pin voltage is 1.22V referenced
to ground, and the output voltage range is 1.22V to 60V.
OUT (Pin 5/Pin 1): Output. The output supplies power to
the load. A minimum output capacitor of 0.47µF is required
to prevent oscillations. Larger output capacitors will be
required for applications with large transient loads to limit
peak voltage transients. See the Applications Information
section for more information on output capacitance and
reverse output characteristics.
NC (Pin 3/Pins 3, 5, 6, 7): No Connect. No Connect pins
may be floated, tied to IN or tied to GND.
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7
LT3014B
APPLICATIONS INFORMATION
Adjustable Operation
The LT3014B has an output voltage range of 1.22V to
60V. The output voltage is set by the ratio of two external
resistors as shown in Figure 1. The device servos the
output to maintain the voltage at the adjust pin at 1.22V
referenced to ground. The current in R1 is then equal to
1.22V/R1 and the current in R2 is the current in R1 plus
the ADJ pin bias current. The ADJ pin bias current, 4nA
at 25°C, flows through R2 into the ADJ pin. The output
voltage can be calculated using the formula in Figure 1.
The value of R1 should be less than 1.62M to minimize
errors in the output voltage caused by the ADJ pin bias
current. The device is tested and specified with the ADJ pin
tied to the OUT pin and a 5µA DC load (unless otherwise
specified) for an output voltage of 1.22V. Specifications
for output voltages greater than 1.22V will be proportional to the ratio of the desired output voltage to 1.22V
(VOUT/1.22V). For example, load regulation for an output
current change of 1mA to 20mA is –13mV typical at VOUT
= 1.22V. At VOUT = 12V, load regulation is:
(12V/1.22V) • (–13mV) = –128mV
IN
VIN
OUT
R2
LT3014B
VOUT
+
ADJ
GND
R1
Output Capacitance and Transient Response
The LT3014B is designed to be stable with a wide range of
output capacitors. The ESR of the output capacitor affects
stability, most notably with small capacitors. A minimum
output capacitor of 0.47µF with an ESR of 3Ω or less is
recommended to prevent oscillations. The LT3014B is a
micropower device and output transient response will be
a function of output capacitance. Larger values of output
capacitance decrease the peak deviations and provide
improved transient response for larger load current
changes. Bypass capacitors, used to decouple individual
components powered by the LT3014B, will increase the
effective output capacitor value.
Extra consideration must be given to the use of ceramic
capacitors. Ceramic capacitors are manufactured with a
variety of dielectrics, each with different behavior across
temperature and applied voltage. The most common
dielectrics used are specified with EIA temperature characteristic codes of Z5U, Y5V, X5R and X7R. The Z5U and
Y5V dielectrics are good for providing high capacitances
in a small package, but they tend to have strong voltage
and temperature coefficients as shown in Figures 2 and 3.
When used with a 5V regulator, a 16V 10µF Y5V capacitor
can exhibit an effective value as low as 1µF to 2µF for the
DC bias voltage applied and over the operating temperature range. The X5R and X7R dielectrics result in more
stable characteristics and are more suitable for use as the
output capacitor. The X7R type has better stability across
temperature, while the X5R is less expensive and is avail20
BOTH CAPACITORS ARE 16V,
1210 CASE SIZE, 10µF
0
CHANGE IN VALUE (%)
The LT3014B is a 20mA high voltage, low dropout regulator with micropower quiescent current. The device is
capable of supplying 20mA at a dropout voltage of 350mV.
Operating quiescent current is only 7µA. In addition to
the low quiescent current, the LT3014B incorporates
several protection features which make it ideal for use in
battery-powered systems. The device is protected against
both reverse input and reverse output voltages. In battery
backup applications where the output can be held up by
a backup battery when the input is pulled to ground, the
LT3014B acts like it has a diode in series with its output
and prevents reverse current flow.
X5R
–20
–40
–60
Y5V
3014B F01
–80
( )
VOUT = 1.22V • 1 + R2 + (IADJ)(R2)
R1
VADJ = 1.22V
IADJ = 4nA AT 25°C
OUTPUT RANGE = 1.22V TO 60V
Figure 1. Adjustable Operation
8
–100
0
2
4
8
6
10 12
DC BIAS VOLTAGE (V)
14
16
3014B F02
Figure 2. Ceramic Capacitor DC Bias Characteristics
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LT3014B
APPLICATIONS INFORMATION
The GND pin current can be found by examining the GND
Pin Current curves in the Typical Performance Characteristics. Power dissipation will be equal to the sum of the
two components listed above.
40
CHANGE IN VALUE (%)
20
0
X5R
–20
–40
Y5V
–60
–80
BOTH CAPACITORS ARE 16V,
1210 CASE SIZE, 10µF
–100
–50 –25
50
25
75
0
TEMPERATURE (°C)
100
125
3014B F03
Figure 3. Ceramic Capacitor Temperature Characteristics
able in higher values. Care still must be exercised when
using X5R and X7R capacitors; the X5R and X7R codes
only specify operating temperature range and maximum
capacitance change over temperature. Capacitance change
due to DC bias with X5R and X7R capacitors is better than
Y5V and Z5U capacitors, but can still be significant enough
to drop capacitor values below appropriate levels. Capacitor DC bias characteristics tend to improve as component
case size increases, but expected capacitance at operating
voltage should be verified.
Voltage and temperature coefficients are not the only
sources of problems. Some ceramic capacitors have a
piezoelectric response. A piezoelectric device generates
voltage across its terminals due to mechanical stress,
similar to the way a piezoelectric accelerometer or microphone works. For a ceramic capacitor the stress can be
induced by vibrations in the system or thermal transients.
The LT3014B regulator has internal thermal limiting designed to protect the device during overload conditions.
For continuous normal conditions the maximum junction
temperature rating of 125°C must not be exceeded. It is
important to give careful consideration to all sources of
thermal resistance from junction to ambient. Additional
heat sources mounted nearby must also be considered.
For surface mount devices, heat sinking is accomplished
by using the heat spreading capabilities of the PC board
and its copper traces. Copper board stiffeners and plated
through-holes can also be used to spread the heat generated by power devices.
The following table lists thermal resistance for several
different board sizes and copper areas. All measurements
were taken in still air on 3/32” FR-4 board with one ounce
copper.
Table 1. SOT-23 Measured Thermal Resistance
COPPER AREA
BOARD AREA
THERMAL RESISTANCE
(JUNCTION-TO-AMBIENT)
2500 sq mm 2500 sq mm
2500 sq mm
125°C/W
1000 sq mm 2500 sq mm
2500 sq mm
125°C/W
225 sq mm
2500 sq mm
2500 sq mm
130°C/W
100 sq mm
2500 sq mm
2500 sq mm
135°C/W
50 sq mm
2500 sq mm
2500 sq mm
150°C/W
TOPSIDE
BACKSIDE
Table 2. DFN Measured Thermal Resistance
COPPER AREA
Thermal Considerations
The power handling capability of the device will be limited
by the maximum rated junction temperature (125°C). The
power dissipated by the device will be made up of two
components:
1. Output current multiplied by the input/output voltage
differential: IOUT • (VIN – VOUT) and,
2. GND pin current multiplied by the input voltage:
IGND • VIN.
BOARD AREA
THERMAL RESISTANCE
(JUNCTION-TO-AMBIENT)
2500 sq mm 2500 sq mm
2500 sq mm
40°C/W
1000 sq mm 2500 sq mm
2500 sq mm
45°C/W
225 sq mm
2500 sq mm
2500 sq mm
50°C/W
100 sq mm
2500 sq mm
2500 sq mm
62°C/W
TOPSIDE
BACKSIDE
For the DFN package, the thermal resistance junction-tocase (θJC), measured at the Exposed Pad on the back of
the die, is 16°C/W.
3014bfb
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9
LT3014B
APPLICATIONS INFORMATION
Continuous operation at large input/output voltage differentials and maximum load current is not practical due
to thermal limitations. Transient operation at high input/
output differentials is possible. The approximate thermal
time constant for a 2500sq mm 3/32" FR-4 board with
maximum topside and backside area for one ounce copper is 3 seconds. This time constant will increase as more
thermal mass is added (i.e. vias, larger board, and other
components).
For an application with transient high power peaks, average
power dissipation can be used for junction temperature
calculations as long as the pulse period is significantly less
than the thermal time constant of the device and board.
Calculating Junction Temperature
Example 1: Given an output voltage of 5V, an input voltage range of 24V to 30V, an output current range of 0mA
to 20mA, and a maximum ambient temperature of 50°C,
what will the maximum junction temperature be?
The power dissipated by the device will be equal to:
IOUT(MAX) • (VIN(MAX) – VOUT) + (IGND • VIN(MAX))
Example 2: Given an output voltage of 5V, an input voltage
of 48V that rises to 72V for 5ms(max) out of every 100ms,
and a 5mA load that steps to 20mA for 50ms out of every
250ms, what is the junction temperature rise above ambient? Using a 500ms period (well under the time constant
of the board), power dissipation is as follows:
P1(48V in, 5mA load) = 5mA • (48V – 5V)
+ (100µA • 48V) = 0.22W
P2(48V in, 20mA load) = 20mA • (48V – 5V)
+ (0.55mA • 48V) = 0.89W
P3(72V in, 5mA load) = 5mA • (72V – 5V)
+ (100µA • 72V) = 0.34W
P4(72V in, 20mA load) = 20mA • (72V – 5V)
+ (0.55mA • 72V) = 1.38W
Operation at the different power levels is as follows:
76% operation at P1, 19% for P2, 4% for P3, and
1% for P4.
PEFF = 76%(0.22W) + 19%(0.89W) + 4%(0.34W)
+ 1%(1.38W) = 0.36W
IOUT(MAX) = 20mA
With a thermal resistance in the range of 40°C/W to
62°C/W, this translates to a junction temperature rise
above ambient of 20°C.
VIN(MAX) = 30V
Protection Features
where:
IGND at (IOUT = 20mA, VIN = 30V) = 0.55mA
So:
P = 20mA • (30V – 5V) + (0.55mA • 30V) = 0.52W
The thermal resistance for the DFN package will be in the
range of 40°C/W to 62°C/W depending on the copper
area. So the junction temperature rise above ambient will
be approximately equal to:
0.52W • 50°C/W = 26°C
The maximum junction temperature will then be equal to
the maximum junction temperature rise above ambient
plus the maximum ambient temperature or:
TJMAX = 50°C + 26°C = 76°C
The LT3014B incorporates several protection features
which make it ideal for use in battery-powered circuits.
In addition to the normal protection features associated
with monolithic regulators, such as current limiting and
thermal limiting, the device is protected against reverseinput voltages, and reverse voltages from output to input.
Current limit protection and thermal overload protection
are intended to protect the device against current overload
conditions at the output of the device. For normal operation, the junction temperature should not exceed 125°C.
The input of the device will withstand reverse voltages of
80V. Current flow into the device will be limited to less
than 6mA (typically less than 100µA) and no negative
3014bfb
10
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LT3014B
APPLICATIONS INFORMATION
The ADJ pin can be pulled above or below ground by as
much as 7V without damaging the device. If the input is
left open circuit or grounded, the ADJ pin will act like an
open circuit when pulled below ground, and like a large
resistor (typically 100k) in series with a diode when pulled
above ground. If the input is powered by a voltage source,
pulling the ADJ pin below the reference voltage will cause
the device to current limit. This will cause the output to
go to an unregulated high voltage. Pulling the ADJ pin
above the reference voltage will turn off all output current.
In situations where the ADJ pin is connected to a resistor
divider that would pull the ADJ pin above its 7V clamp voltage if the output is pulled high, the ADJ pin input current
must be limited to less than 5mA. For example, a resistor
divider is used to provide a regulated 1.5V output from
the 1.22V reference when the output is forced to 60V.
The top resistor of the resistor divider must be chosen to
limit the current into the ADJ pin to less than 5mA when
the ADJ pin is at 7V. The 53V difference between the OUT
and ADJ pins divided by the 5mA maximum current into
the ADJ pin yields a minimum top resistor value of 10.6k.
In circuits where a backup battery is required, several
different input/output conditions can occur. The output
voltage may be held up while the input is either pulled
to ground, pulled to some intermediate voltage, or is left
open circuit. Current flow back into the output will follow
the curve shown in Figure 4. The rise in reverse output
current above 7V occurs from the breakdown of the 7V
clamp on the ADJ pin. With a resistor divider on the
regulator output, this current will be reduced depending
on the size of the resistor divider.
When the IN pin of the LT3014B is forced below the OUT
pin or the OUT pin is pulled above the IN pin, input current will typically drop to less than 2µA. This can happen
if the input of the LT3014B is connected to a discharged
(low voltage) battery and the output is held up by either
a backup battery or a second regulator circuit.
50
REVERSE OUTPUT CURRENT (µA)
voltage will appear at the output. The device will protect
both itself and the load. This provides protection against
batteries which can be plugged in backward.
TJ = 25°C
45 VIN = 0V
= VADJ
V
40 OUT
ADJ PIN
ESD CLAMP
35
30
25
20
CURRENT FLOWS
INTO OUTPUT PIN
15
10
5
0
0
1
2
3 4 5 6 7 8
OUTPUT VOLTAGE (V)
9
10
3014B F04
Figure 4. Reverse Output Current
3014bfb
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11
LT3014B
TYPICAL APPLICATIONS
LT3014B Automotive Application
VIN
12V
(LATER 42V)
+
1µF
IN
NO PROTECTION
DIODE NEEDED!
OUT
LT3014B
R1
1µF
ADJ
GND
R2
LOAD: CLOCK,
SECURITY SYSTEM
ETC
LT3014B Telecom Application
VIN
48V
(72V TRANSIENT)
IN
1µF
OUT
LT3014B
ADJ
GND
R1 NO PROTECTION
DIODE NEEDED!
R2
1µF
+
LOAD:
SYSTEM MONITOR
ETC
–
BACKUP
BATTERY
3014B TA05
3014bfb
12
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LT3014B
PACKAGE DESCRIPTION
Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.
S5 Package
5-Lead Plastic TSOT-23
(Reference LTC DWG # 05-08-1635)
0.62
MAX
0.95
REF
2.90 BSC
(NOTE 4)
1.22 REF
1.4 MIN
3.85 MAX 2.62 REF
2.80 BSC
1.50 – 1.75
(NOTE 4)
PIN ONE
RECOMMENDED SOLDER PAD LAYOUT
PER IPC CALCULATOR
0.30 – 0.45 TYP
5 PLCS (NOTE 3)
0.95 BSC
0.80 – 0.90
0.20 BSC
0.01 – 0.10
1.00 MAX
DATUM ‘A’
0.30 – 0.50 REF
0.09 – 0.20
(NOTE 3)
NOTE:
1. DIMENSIONS ARE IN MILLIMETERS
2. DRAWING NOT TO SCALE
3. DIMENSIONS ARE INCLUSIVE OF PLATING
4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR
5. MOLD FLASH SHALL NOT EXCEED 0.254mm
6. JEDEC PACKAGE REFERENCE IS MO-193
1.90 BSC
S5 TSOT-23 0302
3014bfb
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13
LT3014B
PACKAGE DESCRIPTION
Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.
DD Package
8-Lead Plastic DFN (3mm × 3mm)
(Reference LTC DWG # 05-08-1698 Rev C)
0.70 ±0.05
3.5 ±0.05
1.65 ±0.05
2.10 ±0.05 (2 SIDES)
PACKAGE
OUTLINE
0.25 ±0.05
0.50
BSC
2.38 ±0.05
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED
PIN 1
TOP MARK
(NOTE 6)
0.200 REF
3.00 ±0.10
(4 SIDES)
R = 0.125
TYP
5
0.40 ±0.10
8
1.65 ±0.10
(2 SIDES)
0.75 ±0.05
4
0.25 ±0.05
1
(DD8) DFN 0509 REV C
0.50 BSC
2.38 ±0.10
0.00 – 0.05
BOTTOM VIEW—EXPOSED PAD
NOTE:
1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (WEED-1)
2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE
5. EXPOSED PAD SHALL BE SOLDER PLATED
6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION
ON TOP AND BOTTOM OF PACKAGE
3014bfb
14
For more information www.linear.com/LT3014B
LT3014B
REVISION HISTORY
(Revision history begins at Rev B)
REV
DATE
DESCRIPTION
PAGE NUMBER
B
11/14
Add MP-Grade
2, 3, 4
Modified Related Parts
16
3014bfb
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection
of its circuits
as described
herein will not infringe on existing patent rights.
For more
information
www.linear.com/LT3014B
15
LT3014B
TYPICAL APPLICATIONS
Constant Brightness for Indicator LED over Wide Input Voltage Range
RETURN
IN
OUT
LT3014B
1µF
–48V
1µF
ADJ
GND
ILED = 1.22V/RSET
–48V CAN VARY FROM –3.3V TO –80V
RSET
3014B TA06
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LT1129
700mA, Micropower, LDO
VIN: 4.2V to 30V, VOUT(MIN) = 3.75V, VDO = 0.4V, IQ = 50µA, ISD = 16µA,
DD, SOT-223, S8, TO220, TSSOP-20 Packages
LT1175
500mA, Micropower Negative LDO
VIN: –20V to –4.3V, VOUT(MIN) = –3.8V, VDO = 0.50V, IQ = 45µA, ISD = 10µA,
DD, SOT-223, S8 Packages
LT1185
3A, Negative LDO
VIN: –35V to –4.2V, VOUT(MIN) = –2.40V, VDO = 0.80V, IQ = 2.5mA, ISD < 1µA,
TO220-5 Package
LT1761
100mA, Low Noise Micropower, LDO
VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 20µA, ISD < 1µA,
ThinSOT Package
LT1762
150mA, Low Noise Micropower, LDO
VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 25µA, ISD < 1µA,
MS8 Package
LT1763
500mA, Low Noise Micropower, LDO
VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 30µA, ISD < 1µA,
S8 and DFN Packages
LT1764/LT1764A
3A, Low Noise, Fast Transient Response, LDO
VIN: 2.7V to 20V, VOUT(MIN) = 1.21V, VDO = 0.34V, IQ = 1mA, ISD < 1µA,
DD, TO220 Packages
LTC1844
150mA, Very Low Dropout LDO
VIN: 1.6V to 6.5V, VOUT(MIN) = 1.25V, VDO = 0.08V, IQ = 40µA, ISD < 1µA,
ThinSOT Package
LT1962
300mA, Low Noise Micropower, LDO
VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.27V, IQ = 30µA, ISD < 1µA,
MS8 Package
LT1963/LT1963A
1.5A, Low Noise, Fast Transient Response, LDO
VIN: 2.1V to 20V, VOUT(MIN) = 1.21V, VDO = 0.34V, IQ = 1mA, ISD < 1µA,
DD, TO220, SOT-223 and S8 Packages
LT1964
200mA, Low Noise Micropower, Negative LDO
VIN: –1.9V to –20V, VOUT(MIN) = –1.21V, VDO = 0.34V, IQ = 30µA, ISD = 3µA,
ThinSOT and DFN Packages
LT3010
50mA, 80V, Low Noise Micropower, LDO
VIN: 3V to 80V, VOUT(MIN) = 1.28V, VDO = 0.3V, IQ = 30µA, ISD < 1µA,
MS8E Package
LT3020
100mA, Low VIN, Low VOUT Micropower, VLDO
VIN: 0.9V to 10V, VOUT(MIN) = 0.20V, VDO = 0.15V, IQ = 120µA, ISD < 1µA,
DFN, MS8 Packages
LT3023
Dual 100mA, Low Noise Micropower, LDO
VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 40µA, ISD < 1µA,
DFN, MS10 Packages
LT3024
Dual 100mA/500mA, Low Noise Micropower, LDO
VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 60µA, ISD < 1µA,
DFN, TSSOP-16E Packages
LT3027
Dual 100mA, Low Noise LDO with Independent
Inputs
VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 40µA, ISD < 1µA,
DFN, MS10E Packages
LT3028
Dual 100mA/500mA, Low Noise LDO with
Independent Inputs
VIN: 1.8V to 20V, VOUT(MIN) = 1.22V, VDO = 0.30V, IQ = 60µA, ISD < 1µA,
DFN, TSSOP-16E Packages
3014bfb
16 Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
For more information www.linear.com/LT3014B
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com/LT3014B
LT 1114 REV B • PRINTED IN USA
LINEAR TECHNOLOGY CORPORATION 2006
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