LM138 (Linear Technology)
5A Positive Adjustable Voltage Regulator

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OBSOLETE:
FOR INFORMATION PURPOSES ONLY
Contact Linear Technology for Potential Replacement
Features
nn Guaranteed 1% Initial Tolerance
nn Guaranteed 0.3% Load Regulation
nn Guaranteed 5A Output Current
nn 100% Thermal Limit Burn-In
nn 12A Transient Output Current
Applications
nn High Power Linear Regulator
nn Battery Chargers
nn Power Driver
nn Constant-Current Regulator
Typical Application
Parallel Regulators for Higher Current*
LT338A
0.01Ω∗∗
VIN VIN VOUT
ADJ
5V
8A
LT350A
VIN VOUT
ADJ
0.016Ω**
121Ω
1%
365Ω
1%
138/338 TA01
*THIS CIRCUIT WILL NOT WORK WITH LM VERSION DEVICES
**CURRENT SHARING RESISTORS DEGRADE REGULATION TO 1%
LT138A/LT338A
LM138/LM338
5A Positive Adjustable
Voltage Regulator
Description
The LT®138A series of adjustable regulators provide 5A
output current over an output voltage range of 1.2V to
32V. The internal voltage reference is trimmed to less
than 1%, enabling a very tight output voltage. In addition
to excellent line and load regulation, with full overload
protection, the LT138A incorporates new current limit-
ing circuitry allowing large transient load currents to be
handled for short periods. Transient load currents of up
to 12A can be supplied without limiting, eliminating the
need for a large output capacitor.
The LT138A is an improved version of the popular LM138
with improved circuit design and advanced process tech-
niques to provide superior performance and reliability.
The graph below shows the significant improvement in
output voltage tolerance achieved by using the LT138A
or LT338A.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
Output Voltage Error
12
11
10
9
8
2% RESISTORS LM338
7
6
1% RESISTORS LM338
5 LT338A
4 2% RESISTORS
3 LT338A
2 1% RESISTORS
1
0
1 10 100
OUTPUT VOLTAGE (V)
138A/338A TA02
For more information www.linear.com/LT138A
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LM138 (Linear Technology)
5A Positive Adjustable Voltage Regulator

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LT138A/LT339A
LM138/LM338
Absolute Maximum Ratings (Note 1)
Power Dissipation............................... Internally Limited
Input-to-Output Voltage Differential.......................... 35V
Operating Junction Temperature Range
LT138A/LM138.................................. – 55°C to 150°C
LT338A/LM338..................................... 0°C to 125°C
Storage Temperature Range.................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec).................... 300°C
Preconditioning
100% Thermal Limit Burn-In
Pin Configuration
BOTTOM VIEW
VIN
2
1
CASE
IS OUTPUT
ADJ (GND*)
K PACKAGE
2-LEAD TO-3 METAL CAN
TJMAX = 150°C, θJA = 35°C/W, θJA = 1°C/W (LT138A/LT138)
TJMAX = 125°C, θJA = 35°C/W, θJA = 1°C/W (LT338A/LT338)
OBSOLETE PACKAGE
FRONT VIEW
3
2
1
P PACKAGE
3-LEAD PLASTIC TO-3P
TJMAX = 125°C, θJA = 45°C/W
OBSOLETE PACKAGE
VIN
VOUT
ADJ
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LM138 (Linear Technology)
5A Positive Adjustable Voltage Regulator

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LT138A/LT338A
LM138/LM338
E lectrical Characteristics The denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. (Note 2)
SYMBOL PARAMETER
CONDITIONS
LT138A
MIN TYP MAX
LM138
MIN TYP MAX
VREF Reference Voltage
ΔVOUT
ΔVIN
ΔVOUT
ΔVOUT
Line Regulation
Load Regulation
Thermal Regulation
IOUT = 10mA, TJ = 25°C
3V ≤ (VIN – VOUT) ≤ 35V,
10mA ≤ IOUT ≤ 5A, P ≤ 50W
3V ≤ (VIN – VOUT) ≤ 35V, (Note 3)
10mA ≤ IOUT ≤ 5A, (Note 3)
VOUT ≤ 5V
VOUT ≥ 5V
VOUT ≤ 5V
VOUT ≥ 5V
20ms Pulse
l
l
l
l
1.238
1.225
1.250
1.250
0.005
0.02
5
0.1
20
0.3
0.002
1.262
1.270
1.119
1.24
0.01 0.005
0.04 0.02
15 5
0.3 0.1
30 20
0.6 0.3
0.01 0.002
1.29
0.01
0.04
15
0.3
30
0.6
0.01
IADJ
ΔIADJ
ISC
Ripple Rejection
Adjust Pin Current
Adjust Pin Current Change
Minimum Load Current
Current Limit
VOUT = 10V, f = 120Hz
CADJ = 0µF
CADJ = 10µF
10mA ≤ IOUT ≤ 5A,
3V ≤ (VIN – VOUT) ≤ 35V
(VIN – VOUT) = 35V
(VIN – VOUT) ≤ 10V
DC
0.5ms Peak
l
l 60
60
75
60
60 75
l 45 100
45 100
l 0.2 5
0.2 5
l 3.5 5
3.5 5
l5
l6
8
12
58
6 12
ΔVOUT
ΔTemp
Temperature Stability
(VIN – VOUT) = 30V, TJ = 25ºC
l
12
12
1
1
ΔVOUT
ΔTime
Long-Term Stability
TA = 125ºC, 1000 Hours
0.3 1
0.3 1
en RMS Output Noise (% of VOUT) 10HZ ≤ f ≤ 10kHz
θJC Thermal Resistance
Junction-to-Case
K Package
0.001
1
0.003
1
UNITS
V
V
%/V
%/V
mV
%
mV
%
%/W
dB
dB
µA
µA
mA
A
A
A
%
%
%
ºC/W
The denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C.
SYMBOL PARAMETER
CONDITIONS
LT138A
LM138
MIN TYP MAX MIN TYP MAX UNITS
VREF Reference Voltage
ΔVOUT
ΔVIN
ΔVOUT
ΔVOUT
Line Regulation
Load Regulation
Thermal Regulation
IOUT = 10mA
1.238 1.250 1.262
3V ≤ (VIN – VOUT) ≤ 35V,
10mA ≤ IOUT ≤ 5A, P ≤ 50W
l 1.225 1.250 1.270 1.19 1.24 1.29
3V ≤ (VIN – VOUT) ≤ 35V, (Note 3)
l
0.005 0.01
0.02 0.04
0.005 0.03
0.02 0.06
10mA ≤ IOUT ≤ 5A, (Note 3)
VOUT ≤ 5V
VOUT ≥ 5V
VOUT ≤ 5V
VOUT ≥ 5V
20ms Pulse
l
l
5
0.1
20
0.3
0.002
15
0.3
30
0.6
0.02
5
0.1
20
0.3
0.002
25
0.5
50
1
0.02
V
V
%/V
%/V
mV
%
mV
%
%/W
For more information www.linear.com/LT138A
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5A Positive Adjustable Voltage Regulator

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LT138A/LT339A
LM138/LM338
electrical Characteristics The denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C.
SYMBOL
IADJ
ΔIADJ
ISC
ΔVOUT
ΔTemp
ΔVOUT
ΔTime
en
θJC
PARAMETER
Ripple Rejection
Adjust Pin Current
Adjust Pin Current Change
Minimum Load Current
Current Limit
Temperature Stability
CONDITIONS
VOUT = 10V, f = 120Hz
CADJ = 0µF
CADJ = 10µF
10mA ≤ IOUT ≤ 5A,
3V ≤ (VIN – VOUT) ≤ 35V
(VIN – VOUT) = 35V
(VIN – VOUT) ≤ 10V
DC
0.5ms Peak
(VIN – VOUT) = 30V, TJ = 25ºC
Long-Term Stability
TA = 125ºC, 1000 Hours
RMS Output Noise (% of VOUT)
Thermal Resistance
Junction-to-Case
10Hz ≤ f ≤ 10kHz
K Package
LT138A
LM138
MIN TYP MAX MIN TYP MAX UNITS
l
l 60
l
l
60 60
75 60 75
45 100
45 100
0.2 5
0.2 5
dB
dB
µA
µA
l
3.5 10
3.5 10
mA
l5
l6
l
8
12
12
12
58
6 12
1
1
A
A
A
%
0.3 1
0.3 1
%
0.001
1
0.003
1
%
ºC/W
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: Unless otherwise specified, these specifications apply: VIN – VOUT
= 5V and IOUT = 2.5A. These specifications are applicable for power
dissipations up to 50W.
Note 3: See thermal regulation specifications for changes in output voltage
due to heating effects. Load and line regulation are measured at a constant
junction temperature by low duty cycle pulse testing.
Typical Performance Characteristics
Load Regulation
0.2 VIN = 15V
0.1
VOUT = 10V
PRELOAD = 50mA
0 IOUT = 3A
–0.1 IOUT = 5A
–0.2
–0.3
–0.4
–75 –50 –25 0 25 50 75 100 125 150
TEMPERATURE (°C)
138/338 G01
Dropout Voltage
4 ΔVOUT = 100mV
3
IOUT = 5A
IOUT = 3A
2
IOUT = 1A
1
–75 –50 –25 0 25 50 75 100 125 150
TEMPERATURE (°C)
138/338 G02
4 For more information www.linear.com/LT138A
Adjustment Current
65
60
55
50
45
40
35
30
–75
–25 25 75
TEMPERATURE (°C)
125
138A/338A G03
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5A Positive Adjustable Voltage Regulator

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Typical Performance Characteristics
LT138A/LT338A
LM138/LM338
Temperature Stability
1.270
1.260
1.250
1.240
Output Impedance
10 VIN = 15V
VOUT = 10V
1 IOUT = 500mA
0.1 CADJ = COUT = 0μF
0.01
0.001
CADJ = COUT = 10μF
1.230
–50 –25
0 25 50 75 100 125 150
TEMPERATURE (°C)
138A/338A G04
0.0001
10
100 1k 10k 100k
FREQUENCY (Hz)
1M
138/338 G05
Ripple Rejection
100
CADJ = 10μF
80
CADJ = 0μF
60
40
20
VIN – VOUT = 5V
IOUT = 500mA
f = 120Hz
TJ = 25°C
0
0 5 10 15
20
25
OUTPUT VOLTAGE (V)
30 35
138A/338A G07
Ripple Rejection
100
80 CADJ = 10μF
60
CADJ = 0μF
40
20 VIN = 15V
VOUT = 10V
0 IOUT = 0.2A
10 100
1k 10k
FREQUENCY (Hz)
100k 1M
138A/338A G08
Current Limit
16 PEAK CURRENT LIMIT
DC CURRENT LIMIT
TCASE = 25°C
12 PRELOAD = 0A
PRELOAD = 5A
8
PRELOAD = 1A
4
0
0 10 20 30 40
INPUT-OUTPUT DIFFERENTIAL (V)
138A/338A G10
Current Limit
14
12
PRELOAD = 0A
10
PRELOAD = 5A
8
6
4
2
VVIONU=T
10V
= 5V
0 TCASE = 25°C
0.1 1
10
TIME (ms)
100
138A/338A G11
For more information www.linear.com/LT138A
Minimum Operating Current
5
4
TJ = 150°C
TJ = 25°C
3
2 TJ = –55°C
1
0
0 5 10 15 20 25 30 35 40
INPUT-OUTPUT DIFFERENTIAL (V)
138A/338A G06
Ripple Rejection
80
CADJ = 10μF
70
CADJ = 0μF
60
50 VIN = 15V
VOUT = 10V
f = 120Hz
40 TCASE = 25°C
0.1
1
OUTPUT CURRENT (A)
10
138/338 G09
Current Limit
14
12
PRELOAD CURRENT = 0
TCASE = 25°C
10
VIN – VOUT = 10V
8
6 VIN – VOUT = 15V
4 VIN – VOUT = 20V
2 VIN – VOUT = 30V
0
0.1
1 10
TIME (ms)
100
138A/338A G12
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5A Positive Adjustable Voltage Regulator

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LT138A/LT339A
LM138/LM338
typical performance characteristics
Line Transient Response
1.5 VOUT = 10V
1.0 IOUT = 50mA
0.5 TJ = 25°C
CL = 1μF
CL = 10μF
0
–0.5
–1.0
COUT = 0
CADJ = 0
–1.5
1.0
0.5
0
0
10 20
TIME (μs)
30 40
138A/338A G13
Load Transient Response
3
2 CL = 1μF
1 CADJ = 10μF
CL = 0
CADJ = 0
0
–1
–2
VIN = 15V
VOUT = 10V
–3
TCASE = 25°C
PRELOAD = 100mA
6
4
2
0
0
10 20
TIME (μs)
30
40
138A/338A G14
Applications Information
General
The LT138A develops a 1.25V reference voltage between
the output and the adjustable terminal (see Figure 1). By
placing a resistor, R1, between these two terminals, a
constant current is caused to flow through R1 and down
through R2 to set the overall output voltage. Normally
this current is the specified minimum load current of 5mA
or 10mA. Because IADJ is very small and constant when
compared with the current through R1, it represents a small
error and can usually be ignored. It is easily seen from the
output voltage equation, that even if the resistors were of
exact value, the accuracy of the output is limited by the ac-
curacy of VREF. Earlier adjustable regulators had a reference
tolerance of ± 4% which is dangerously close to the
±5% supply tolerance required in many logic and analog
systems. Further, even 1% resistors can drift 0.01%/°C,
adding additional error to the output voltage tolerance.
VIN
+
LT338A
VIN VOUT
VOUT
ADJ VREF R1
IADJ
50μA
R2
For example, using 2% resistors and ± 4% tolerance for
VREF, calculations will show that the expected range of a
5V regulator design would be 4.66V ≤ VOUT ≤ 5.36V or
approximately ±7%. If the same example were used for a
15V regulator, the expected tolerance would be ±8%. With
these results most applications required some method of
trimming, usually a trim pot. This solution is both expensive
and not conductive to volume production.
One of the enhancements of Linear Technology’s adjust-
able regulators over existing devices is the tightened initial
tolerance of VREF . This allows relatively inexpensive 1%
or 2% film resistors to be used for R1 and R2 to set the
output voltage within an acceptable tolerance.
With a guaranteed 1% reference, a 5V power supply
design, using ± 2% resistors, would have a worst-case
manufacturing tolerance of ±4%. If 1% resistors are used,
the tolerance will drop to ±2.5%. A plot of the worst-case
output voltage tolerance as a function of resistor tolerance
is shown on the front page of this data sheet.
For convenience, a table of standard 1% resistor values
is shown in Table 1.
( )VOUT = VREF
1
+
R2
R1
+ IADJ • R2
138A/338A F01
Figure 1. Basic Adjustable Regulator
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LT138A/LT338A
LM138/LM338
applications information
Table 1. 0.5% and 1% Standard Resistance Values
1.00 1.47 2.15 3.16 4.64 6.81
1.02 1.50 2.21 3.24 4.75 6.98
1.05 1.54 2.26 3.32 4.87 7.15
1.07 1.58 2.32 3.40 4.99 7.32
1.10 1.62 2.37 3.48 5.11 7.50
1.13 1.65 2.43 3.57 5.23 7.68
1.15 1.69 2.49 3.65 5.36 7.87
1.18 1.74 2.55 3.74 5.49 8.06
1.21 1.78 2.61 3.83 5.62 8.25
1.24 1.82 2.67 3.92 5.76 8.45
1.27 1.87 2.74 4.02 5.90 8.66
1.30 1.91 2.80 4.12 6.04 8.87
1.33 1.96 2.87 4.22 6.19 9.09
1.37 2.00 2.94 4.32 6.34 9.31
1.40 2.05 3.01 4.42 6.49 9.53
1.43 2.10 3.09 4.53 6.65 9.76
Standard resistance values are obtained from the Decade Table by
multiplying by multiples of 10. As an example, 1.21 can represent 1.21Ω,
12.1Ω, 121Ω, 1.21k etc.
Bypass Capacitors
Input bypassing using a 1µF tantalum or 25µF electrolytic
is recommended when the input filter capacitors are more
than 5 inches from the device. Improved ripple rejection
(80dB) can be accomplished by adding a 10µF capacitor
from the ADJ pin to ground. Increasing the size of the
capacitor to 20µF will help ripple rejection at low output
voltage since the reactance of this capacitor should be
small compared to the voltage setting resistor, R2. For
improved AC transient response and to prevent the pos-
sibility of oscillation due to unknown reactive load, a 1µF
capacitor is also recommended at the output. Because of
their low impedance at high frequencies, the best type of
capacitor to use is solid tantalum.
Protection Diodes
The LT138A/LT338A do not require a protection diode
from the adjustment terminal to the output (see Figure 2).
Improved internal circuitry eliminates the need for this
diode when the adjustment pin is bypassed with a capaci-
tor to improve ripple rejection.
If a very large output capacitor is used, such as a 100µF
shown in Figure 2, the regulator could be damaged or
destroyed if the input is accidentally shorted to ground
or crowbarred, due to the output capacitor discharging
into the output terminal of the regulator. To prevent this, a
diode D1 as shown, is recommended to safely discharge
the capacitor.
D1
1N4002
LT338A
VIN VIN VOUT
VOUT
ADJ
R1
NOT
NEEDED
CADJ
10μF
R2
+ COUT
100μF
138A/338A F02
Figure 2
Load Regulation
Because the LT138A is a three-terminal device, it is not
possible to provide true remote load sensing. Load regula-
tion will be limited by the resistance of the wire connecting
the regulator to the load. The data sheet specification for
load regulation is measured at the bottom of the package.
Negative side sensing is a true Kelvin connection, with the
bottom of the output divider returned to the negative side
of the load. Although it may not be immediately obvious,
best load regulation is obtained when the top of the resis-
tor divider, R1, is connected directly to the case not to the
load. This is illustrated in Figure 3. If R1 were connected
to the load, the effective resistance between the regulator
and the load would be:
RP ⎛⎝⎜R2R+1R1⎞⎠⎟,RP = Parasitic Line Resistance
Connected as shown, RP is not multiplied by the divider
ratio. RP is about 0.004Ω per foot using 16 gauge wire. This
translates to 4mV/ft at 1A load current, so it is important
to keep the positive lead between regulator and load as
short as possible, and use large wire or PC board traces.
For more information www.linear.com/LT138A
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LT138A/LT339A
LM138/LM338
applications information
LT338A
RP
PARASITIC
LINE RESISTANCE
VIN VIN VOUT
ADJ CONNECT
R1 TO CASE
R1
RL
R2
CONNECT
R2 TO LOAD
138A/338A F03
Figure 3. Connections for Best Load Regulation
Typical Applications
Improving Ripple Rejection
LT338A
VIN
+
VIN
1μF
VOUT
ADJ
R1
121Ω
1%
R2 +
365Ω
1%
5V
CL*
10μF
*C1 IMPROVES RIPPLE REJECTION, XC
SHOULD BE SMALL COMPARED TO R2
138A/338A TA03
1.2V to 25V Adjustable Regulator
LT338A
VIN VIN VOUT
ADJ
+ C1*
1μF
R2
5k
R1
240Ω
+
VOUT
C2**
1μF
138A/338A TA04
*NEEDED IF DEVICE IS FAR FROM FILTER CAPACITORS
**OPTIONAL, IMPROVES TRANSIENT RESPONSE
( )VOUT = 1.25V
1
+
R2
R1
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5A Positive Adjustable Voltage Regulator

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typical Applications
5V Regulator with Shutdown
LT338A
VIN
+
VIN VOUT
ADJ
1μF
1k
TTL
2N3904
1k
5V
121Ω
1%
365Ω
1%
138A/338A TA05
LT138A/LT338A
LM138/LM338
Temperature Compensated Lead Acid Battery Charger
3A LT338A
VIN VOUT
ADJ
50Ω
2N3906
243Ω
1%
10k
12V
2k
50k
138A/338A TA07
LT338A
VIN VIN
VOUT
ADJ
RETURN
Remote Sensing
RP
(MAX DROP
300mV)
VIN
72
25Ω 6
LM301A
121Ω
1
3 1k
84
5μF
365Ω
100pF
25Ω
VOUT
5V
RL
138A/338A TA06
RETURN
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5A Positive Adjustable Voltage Regulator

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LT138A/LT339A
LM138/LM338
Schematic Diagram LT138A/LT338A
10
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LT138A/LT338A
LM138/LM338
Package Description
Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.
K Package
2-Lead TO-3 Metal Can
(Reference LTC DWG # 05-08-1310)
0.320 – 0.350
(8.13 – 8.89)
0.760 – 0.775
(19.30 – 19.69)
0.060 – 0.135
(1.524 – 3.429)
0.420 – 0.480
(10.67 – 12.19)
0.038 – 0.043
(0.965 – 1.09)
0.210 – 0.220
(5.33 – 5.59)
1.177 – 1.197
(29.90 – 30.40)
0.655 – 0.675
(16.64 – 17.15)
0.151 – 0.161
(3.86 – 4.09)
DIA, 2PLCS
0.425 – 0.435
(10.80 – 11.05)
0.067 – 0.077
(1.70 – 1.96)
0.167 – 0.177
(4.24 – 4.49)
R
0.490 – 0.510
(12.45 – 12.95)
R
K2 (TO-3) 1098
OBSOLETE PACKAGE
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LT138A/LT339A
LM138/LM338
Package Description
Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.
P Package
3-Lead Plastic TO-3P (Similar to TO-247)
(Reference LTC DWG # 05-08-1450)
.560
(14.224)
.325
(8.255)
.275
(6.985)
.580
(14.732)
.700
(17.780)
.830 – .870
(21.08 – 22.10)
.580 – .6OO
(14.73 – 15.24)
.620 – .64O
(15.75 – 16.26)
MOUNTING HOLE
.115 – .145
(2.92 – 3.68)
DIA
18 – 22
.170 – .2OO
(4.32 – 5.08)
EJECTOR PIN MARKS
.105 – .125
(2.67 – 3.18)
DIA
.098
(2.489)
.124
(3.149)
.170
(4.32)
MAX
.780 – .800
(19.81 – 20.32)
3–7
BOTTOM VIEW OF TO-3P
HATCHED AREA IS SOLDER PLATED
COPPER HEAT SINK
.042 – .052
(1.07 – 1.32)
.074 – .084
(1.88 – 2.13)
.215
(5.46)
BSC
.113 – .123
(2.87 – 3.12)
OBSOLETE PACKAGE
.187 – .207
(4.75 – 5.26)
.060 – .080
(1.52 – 2.03)
.087 – .102
(2.21 – 2.59)
.020 – .040
(0.51 – 1.02)
P3 0801
12
For more information www.linear.com/LT138A
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LM138 (Linear Technology)
5A Positive Adjustable Voltage Regulator

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Revision History (Revision history begins at Rev D)
REV DATE DESCRIPTION
D 05/15 Obsolete packaged parts.
LT138A/LT338A
LM138/LM338
PAGE NUMBER
1, 2, 12
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 representa-
tion that the interconnecFtoiornmofoitrseciirncfuoitrsmasadtieosncrwibewdwh.elrineienawr.icllonmot/iLnTfr1in3g8eAon existing patent rights.
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13


LM138 (Linear Technology)
5A Positive Adjustable Voltage Regulator

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Click to Download PDF File for PC

LT138A/LT339A
LM138/LM338
Typical Application
Lamp Flasher
15V +
LT338A
VIN VOUT
1μF ADJ
10μF
OFF 12k
1k 12k
2N3904
12k
10μF
10μF
12V
138A/338A TA08
Automatic Light Control
LT338A
VIN VOUT
ADJ
1.2k
138A/338A TA09
Protected High Current Lamp Driver
15V
TTL OR
CMOS
LT338A
VOUT
VIN
ADJ
12V
5A
10k
138A/338A TA10
Related Parts
PART NUMBER
LT1083/LT1084/
LT1085
LT1580
LT1581
LT1584/LT1585/
LT1587
LT1764
DESCRIPTION
3A/5A/7.5A Low Dropout Regulators
7A Fast Transient Response Regulator with 0.7V Dropout
10A Fast Transient Response Regulator
7A/4.6A/3A Low Dropout Fast Transient Response Regulator
3A Fast Transient Response Regulator
COMMENTS
Fixed Outputs, VIN Up to 30V
For 3.3V to 2.xxV Applications
For 3.3V to 2.xxV Applications
For 1.2V to 3.3V Outputs from 5V
Dropout Voltage 340mV, Low Noise: 40µVRMS
14 Linear Technology Corporation
1630 McCarthy Blvd., Milpitas,
(408) 432-1900 FAX: (408) 434-0507
CAww9w5.0lFin3oe5ra-mr.7co4orm1e7/inLTfo1r3m8Aation
www.linear.com/LT138A
138afd
LT 0515 REV D • PRINTED IN USA
LINEAR TECHNOLOGY CORPORATION 1991




LM138.pdf
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