LT1120A Datasheet, PDF (1/8 Pages) Linear Technology – Micropower Regulator with Comparator and Shutdown

FEATURES
s _{20µA Supply Current}
s _{8-Lead SOIC}
s _{125mA Output Current}
s _{2.5V Reference}
s _{Reference Output Sources 4mA and Sinks 4mA}
s _{Open Collector}
s _{Comparator Sinks 10mA}
s _{Logic Shutdown}
s _{0.2V Dropout Voltage}
s _{Thermal Limiting}
U
APPLICATIONS
s _{Battery Systems}
s _{Battery Backup System}
s _{Portable Terminals}
s _{Portable Instruments}
s _{Memory Keep Alive}
LT1120A
Micropower Regulator with
Comparator and Shutdown
DESCRIPTION
The LT1120A 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.
TYPICAL APPLICATION
5V Regulator
V_IN > 5.2V
I_Q = 20µA
10µF
5 _VIN
V_OUT ⁴
LT1120A
GND ^{FB 2}
3
1
SHUTDOWN
0.001µF 1M
1M
5V
25µF
1120A TA01
Dropout Voltage and Supply Current
1.00
10
0.10
1
0.01
0.1
1
10
100
OUTPUT CURRENT (mA)
0.1
1000
1120A TA02
1