LP3872/LP3875
1.5A Fast Ultra Low Dropout Linear Regulators
LP3872/LP3875 1.5A Fast Ultra Low Dropout Linear Regulators
August 2003
General Description
The LP3872/LP3875 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 LP3872/LP3875
are developed on a CMOS process which allows low quiescent current operation independent of output load current.
This CMOS process also allows the LP3872/LP3875 to operate under extremely low dropout conditions.
Dropout Voltage: Ultra low dropout voltage; typically 38mV
at 150mA load current and 380mV at 1.5A load current.
Ground Pin Current: Typically 6mA at 1.5A 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
conditions (varying line, load, and temperature).
±
1.5% at room temperature, and±3.0% over all
Typical Application Circuits
Features
n Ultra low dropout voltage
n Low ground pin current
n Load regulation of 0.06%
n 10nA quiescent current in shutdown mode
n Guaranteed output current of 1.5A DC
n Available in TO-263 and TO-220 packages
n Output voltage accuracy
n Error flag indicates output status
n Sense option improves load regulation
n Minimum output capacitor requirements
n Overtemperature/overcurrent protection
n −40˚C to +125˚C junction temperature range
±
1.5%
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
*SD and ERROR pins must be pulled high through a 10kΩ pull-up resistor. Connect the ERROR pin to ground if this function is not used. See applications
section for more information.
© 2003 National Semiconductor Corporation DS200633 www.national.com
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Typical Application Circuits (Continued)
LP3872/LP3875
*SD must be pulled high through a 10kΩ pull-up resistor. See applications section for more information.
Connection Diagrams
Top View
20063305
TO220-5 Package
Bent, Staggered Leads
Top View
TO263-5 Package
Pin Description for TO220-5 and TO263-5 Packages
#
Pin
Name Function Name Function
1SD
2V
IN
3 GND Ground GND Ground
4V
OUT
5 ERROR
LP3872 LP3875
Shutdown SD Shutdown
Input Supply V
Output Voltage V
IN
OUT
ERROR Flag SENSE Remote Sense Pin
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Input Supply
Output Voltage
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Ordering Information
LP3872/LP3875
Package Type Designator is "T" for TO220 package, and "S" for TO263 package.
TABLE 1. Package Marking and Ordering Information
Output
Voltage Order Number
5.0 LP3872ES-5.0 1.5A, Error Flag
5.0 LP3872ESX-5.0 1.5A, Error Flag
3.3 LP3872ES-3.3 1.5A, Error Flag
3.3 LP3872ESX-3.3 1.5A, Error Flag
2.5 LP3872ES-2.5 1.5A, Error Flag
2.5 LP3872ESX-2.5 1.5A, Error Flag
1.8 LP3872ES-1.8 1.5A, Error Flag
1.8 LP3872ESX-1.8 1.5A, Error Flag
5.0 LP3875ES-5.0 1.5A, SENSE TO263-5 LP3875ES-5.0 Rail
5.0 LP3875ESX-5.0 1.5A, SENSE TO263-5 LP3875ES-5.0 Tape and Reel
3.3 LP3875ES-3.3 1.5A, SENSE TO263-5 LP3875ES-3.3 Rail
3.3 LP3875ESX-3.3 1.5A, SENSE TO263-5 LP3875ES-3.3 Tape and Reel
2.5 LP3875ES-2.5 1.5A, SENSE TO263-5 LP3875ES-2.5 Rail
2.5 LP3875ESX-2.5 1.5A, SENSE TO263-5 LP3875ES-2.5 Tape and Reel
1.8 LP3875ES-1.8 1.5A, SENSE TO263-5 LP3875ES-1.8 Rail
1.8 LP3875ESX-1.8 1.5A, SENSE TO263-5 LP3875ES-1.8 Tape and Reel
5.0 LP3872ET-5.0 1.5A, Error Flag
3.3 LP3872ET-3.3 1.5A, Error Flag
2.5 LP3872ET-2.5 1.5A, Error Flag
1.8 LP3872ET-1.8 1.5A, Error Flag
5.0 LP3875ET-5.0 1.5A, SENSE TO220-5 LP3875ET-5.0 Rail
3.3 LP3875ET-3.3 1.5A, SENSE TO220-5 LP3875ET-3.3 Rail
2.5 LP3875ET-2.5 1.5A, SENSE TO220-5 LP3875ET-2.5 Rail
1.8 LP3875ET-1.8 1.5A, SENSE TO220-5 LP3875ET-1.8 Rail
Description
(Current, Option)
Package
Type Package Marking Supplied As:
TO263-5 LP3872ES-5.0 Rail
TO263-5 LP3872ES-5.0 Tape and Reel
TO263-5 LP3872ES-3.3 Rail
TO263-5 LP3872ES-3.3 Tape and Reel
TO263-5 LP3872ES-2.5 Rail
TO263-5 LP3872ES-2.5 Tape and Reel
TO263-5 LP3872ES-1.8 Rail
TO263-5 LP3872ES-1.8 Tape and Reel
TO220-5 LP3872ET-5.0 Rail
TO220-5 LP3872ET-3.3 Rail
TO220-5 LP3872ET-2.5 Rail
TO220-5 LP3872ET-1.8 Rail
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