LP3871/LP3874
0.8A Fast Ultra Low Dropout Linear Regulators
General Description
The LP3871/LP3874 series of fast ultra low-dropout linear
regulators operate from a +2.5V to +7.0V input supply. Wide
range of preset output voltage options are available. These
ultra low dropout linear regulators respond very quickly to
step changes in load, which makes them suitable for low
voltage microprocessor applications. The LP3871/LP3874
are developed on a CMOS process which allows low quies-
cent current operation independent of output load current.
This CMOS process also allows the LP3871/LP3874 to op-
erate under extremely low dropout conditions.
Dropout Voltage: Ultra low dropout voltage; typically 24mV
at 80mA load current and 240mV at 0.8A load current.
Ground Pin Current: Typically 6mA at 0.8A load current.
Shutdown Mode: Typically 10nA quiescent current when
the shutdown pin is pulled low.
Error Flag: Error flag goes low when the output voltage
drops 10% below nominal value.
SENSE: Sense pin improves regulation at remote loads.
Precision Output Voltage: Multiple output voltage options
are available ranging from 1.8V to 5.0V with a guaranteed
accuracy of
1.5% at room temperature, and
3.0% over all
conditions (varying line, load, and temperature).
Features
n
Ultra low dropout voltage
n
Low ground pin current
n
Load regulation of 0.04%
n
10nA quiescent current in shutdown mode
n
Guaranteed output current of 0.8A DC
n
Available in TO-263, TO-220 and SOT-223 packages
n
Output voltage accuracy
1.5%
n
Error flag indicates output status
n
Sense option improves load regulation
n
Minimum output capacitor requirements
n
Overtemperature/overcurrent protection
n
-40C to +125C junction temperature range
Applications
n
Microprocessor power supplies
n
GTL, GTL+, BTL, and SSTL bus terminators
n
Power supplies for DSPs
n
SCSI terminator
n
Post regulators
n
High efficiency linear regulators
n
Battery chargers
n
Other battery powered applications
Typical Application Circuits
20063101
*SD and ERROR pins must be pulled high through a 10k
pull-up resistor. Connect the ERROR pin to ground if this function is not used. See application hints
for more information.
April 2004
LP3871/LP3874
0.8A
Fast
Ultra
Low
Dropout
Linear
Regulators
2004 National Semiconductor Corporation
DS200631
www.national.com
Ordering Information
20063131
Package Type Designator is "T" for TO220 package, and "S" for TO263 package, and "MP" for SOT-223 package.
TABLE 1. Package Marking and Ordering Information
Output
Voltage
Order Number
Description
(Current, Option)
Package
Type
Package
Marking
Supplied As:
5.0
LP3871ES-5.0
0.8A, Error Flag
TO263-5
LP3871ES-5.0
Rail
5.0
LP3871ESX-5.0
0.8A, Error Flag
TO263-5
LP3871ES-5.0
Tape and Reel
3.3
LP3871ES-3.3
0.8A, Error Flag
TO263-5
LP3871ES-3.3
Rail
3.3
LP3871ESX-3.3
0.8A, Error Flag
TO263-5
LP3871ES-3.3
Tape and Reel
2.5
LP3871ES-2.5
0.8A, Error Flag
TO263-5
LP3871ES-2.5
Rail
2.5
LP3871ESX-2.5
0.8A, Error Flag
TO263-5
LP3871ES-2.5
Tape and Reel
1.8
LP3871ES-1.8
0.8A, Error Flag
TO263-5
LP3871ES-1.8
Rail
1.8
LP3871ESX-1.8
0.8A, Error Flag
TO263-5
LP3871ES-1.8
Tape and Reel
5.0
LP3874ES-5.0
0.8A, SENSE
TO263-5
LP3874ES-5.0
Rail
5.0
LP3874ESX-5.0
0.8A, SENSE
TO263-5
LP3874ES-5.0
Tape and Reel
3.3
LP3874ES-3.3
0.8A, SENSE
TO263-5
LP3874ES-3.3
Rail
3.3
LP3874ESX-3.3
0.8A, SENSE
TO263-5
LP3874ES-3.3
Tape and Reel
2.5
LP3874ES-2.5
0.8A, SENSE
TO263-5
LP3874ES-2.5
Rail
2.5
LP3874ESX-2.5
0.8A, SENSE
TO263-5
LP3874ES-2.5
Tape and Reel
1.8
LP3874ES-1.8
0.8A, SENSE
TO263-5
LP3874ES-1.8
Rail
1.8
LP3874ESX-1.8
0.8A, SENSE
TO263-5
LP3874ES-1.8
Tape and Reel
5.0
LP3871ET-5.0
0.8A, Error Flag
TO220-5
LP3871ET-5.0
Rail
3.3
LP3871ET-3.3
0.8A, Error Flag
TO220-5
LP3871ET-3.3
Rail
2.5
LP3871ET-2.5
0.8A, Error Flag
TO220-5
LP3871ET-2.5
Rail
1.8
LP3871ET-1.8
0.8A, Error Flag
TO220-5
LP3871ET-1.8
Rail
5.0
LP3874ET-5.0
0.8A, SENSE
TO220-5
LP3874ET-5.0
Rail
3.3
LP3874ET-3.3
0.8A, SENSE
TO220-5
LP3874ET-3.3
Rail
2.5
LP3874ET-2.5
0.8A, SENSE
TO220-5
LP3874ET-2.5
Rail
1.8
LP3874ET-1.8
0.8A, SENSE
TO220-5
LP3874ET-1.8
Rail
5.0
LP3871EMP-5.0
0.8A, Error Flag
SOT223-5
LH9B
1000 Units on Tape and Reel
5.0
LP3871EMPX-5.0
0.8A, Error Flag
SOT223-5
LH9B
2000 Units on Tape and Reel
3.3
LP3871EMP-3.3
0.8A, Error Flag
SOT223-5
LH8B
1000 Units on Tape and Reel
3.3
LP3871EMPX-3.3
0.8A, Error Flag
SOT223-5
LH8B
2000 Units on Tape and Reel
2.5
LP3871EMP-2.5
0.8A, Error Flag
SOT223-5
LH7B
1000 Units on Tape and Reel
2.5
LP3871EMPX-2.5
0.8A, Error Flag
SOT223-5
LH7B
2000 Units on Tape and Reel
1.8
LP3871EMP-1.8
0.8A, Error Flag
SOT223-5
LH6B
1000 Units on Tape and Reel
1.8
LP3871EMPX-1.8
0.8A, Error Flag
SOT223-5
LH6B
2000 Units on Tape and Reel
LP3871/LP3874
www.national.com
4
Ordering Information
(Continued)
TABLE 1. Package Marking and Ordering Information (Continued)
Output
Voltage
Order Number
Description
(Current, Option)
Package
Type
Package
Marking
Supplied As:
5.0
LP3874EMP-5.0
0.8A, SENSE
SOT223-5
LHJB
1000 Units on Tape and Reel
5.0
LP3874EMPX-5.0
0.8A, SENSE
SOT223-5
LHJB
2000 Units on Tape and Reel
3.3
LP3874EMP-3.3
0.8A, SENSE
SOT223-5
LHHB
1000 Units on Tape and Reel
3.3
LP3874EMPX-3.3
0.8A, SENSE
SOT223-5
LHHB
2000 Units on Tape and Reel
2.5
LP3874EMP-2.5
0.8A, SENSE
SOT223-5
LHFB
1000 Units on Tape and Reel
2.5
LP3874EMPX-2.5
0.8A, SENSE
SOT223-5
LHFB
2000 Units on Tape and Reel
1.8
LP3874EMP-1.8
0.8A, SENSE
SOT223-5
LHEB
1000 Units on Tape and Reel
1.8
LP3874EMPX-1.8
0.8A, SENSE
SOT223-5
LHEB
2000 Units on Tape and Reel
LP3871/LP3874
www.national.com
5
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