LT1120A
1
1120afb
For more information www.linear.com/LT1120A
Typical applicaTion
FeaTures DescripTion
Micropower Regulator with
Comparator and Shutdown
The LT
®
1120A is a combination micropower positive regu-
lator and free collector comparator on a single monolithic
chip. With only 20µA supply current, the LT1120A can
supply over 125mA of output current. Input voltage range
is from 4.5V to 36V and dropout voltage is 0.6V at 125mA.
Dropout voltage decreases with lower load currents. Also
included on the chip is a class B output 2.5V reference
that can either source or sink current. This allows it to be
used as a supply splitter or auxiliary output. A shutdown
pin allows logic shutdown of the output.
The comparator can be used for system or battery moni
-
toring. For example, the comparator can be used to warn
of low system voltage. Frequency compensation of the
comparator for amplifier applications can be obtained by
adding external output capacitance.
5V Regulator Dropout Voltage and Supply Current
applicaTions
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
ThinSOT is a trademark of Analog Devices, Inc. All other trademarks are the property of their
respective owners.
n
20µA Supply Current
n
125mA Output Current
n
2.5V Reference
n
Reference Output Sources 4mA and Sinks 4mA
n
Open Collector Comparator Sinks 10mA
n
Logic Shutdown
n
0.2V Dropout Voltage
n
Thermal Limiting
n
8-Lead SO Package
n
Battery Systems
n
Battery Backup System
n
Portable Terminals
n
Portable Instruments
n
Memory Keep Alive
1120A TA01a
V
IN
> 5.2V
I
Q
= 20µA
10µF
1M
SHUTDOWN
13
5 4
2
0.001µF
25µF
1M
5V
LT1120A
V
OUT
V
IN
GND
FB
+
+
OUTPUT CURRENT (mA)
0.1
0.01
DROPOUT VOLTAGE (V)
1.00
1 1000
1120A TA01b
10
0.10
100
0.1
SUPPLY CURRENT (mA)
10
1