LT138A/LT338A
LM138/LM338
5A Positive Adjustable
Voltage Regulator
FEATURES
s
s
s
s
s
DESCRIPTIO
Guaranteed
1% Initial Tolerance
Guaranteed
0.3% Load Regulation
Guaranteed
5A Output Current
100% Thermal Limit Burn-In
12A Transient Output Current
APPLICATIO S
s
s
s
s
High Power Linear Regulator
Battery Chargers
Power Driver
Constant-Current Regulator
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 excel-
lent line and load regulation, with full overload protection,
the LT138A incorporates new current limiting 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.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIO
Parallel Regulators for Higher Current*
12
LT338A
V
IN
V
IN
ADJ
V
OUT
0.01Ω**
OUTPUT VOLTAGE ERROR (%)
5V
8A
11
10
9
8
7
6
5
4
3
2
1
0
1% RESISTORS
2% RESISTORS
LT338A
2% RESISTORS
1% RESISTORS
LM338
LM338
LT338A
LT350A
V
IN
ADJ
V
OUT
0.016Ω**
121Ω
1%
365Ω
1%
138/338 TA01
1
*THIS CIRCUIT WILL NOT WORK WITH LM VERSION DEVICES
**CURRENT SHARING RESISTORS DEGRADE REGULATION TO 1%
U
Output Voltage Error
10
OUTPUT VOLTAGE (V)
100
138A/338A TA02
U
U
1
LINER [ LINEAR TECHNOLOGY ]
