LT1120A_04 Datasheet, PDF (1/8 Pages) Linear Technology – Micropower Regulator with Comparator and Shutdown

LT1120A
Micropower Regulator with
Comparator and Shutdown
FEATURES
s _{20µA Supply Current}
s _{125mA Output Current}
s _{2.5V Reference}
s _{Reference Output Sources 4mA and Sinks 4mA}
s _{Open Collector Comparator Sinks 10mA}
s _{Logic Shutdown}
s _{0.2V Dropout Voltage}
s _{Thermal Limiting}
s _{8-Lead SO Package}
U
APPLICATIO S
s _{Battery Systems}
s _{Battery Backup System}
s _{Portable Terminals}
s _{Portable Instruments}
s _{Memory Keep Alive}
DESCRIPTIO
The LT^®1120A is a combination micropower positive
regulator and free collector comparator on a single mono-
lithic 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 cur-
rents. 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.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIO
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
1120afa
1