LT1120_15 Datasheet, PDF (1/12 Pages) Linear Technology – Micropower Regulator with Comparator and Shutdown

LT1120
Micropower Regulator with
Comparator and Shutdown
FEATURES
■ _{40μA Supply Current}
■ _{125mA Output Current}
■ _{2.5V Reference Voltage}
■ _{Reference Output Sources 2mA and Sinks 2mA}
■ _{Open Collector Comparator Sinks 10mA}
■ _{Logic Shutdown}
■ _{0.2V Dropout Voltage}
■ _{Thermal Limiting}
■ Available in 8-Lead DIP and SO Packages
U
APPLICATIO S
■ Battery Systems
■ _{Battery-Backup System}
■ _{Portable Terminals}
■ _{Portable Instruments}
■ _{Memory Keep-Alive}
DESCRIPTIO
The LT^®1120 is a combination micropower positive regu-
lator and free collector comparator on a single monolithic
chip. With only 40μA supply current, the LT1120 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. 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.
The 2.5V reference will source or sink current. This allows
it to be used as a supply splitter or auxiliary output.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATIO
5V Regulator
V_IN > 5.2V
I_Q = 40μA
+
5
V_IN
4
V_OUT
10μF
LT1120
2
FB
SHDN
GND
3
1
0.001μF
5V
1M
+
25μF
1M
SHUTDOWN
1120 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
1120 TA02
1120fd
1