LP3853 Datasheet, PDF (1/18 Pages) National Semiconductor (TI) – 3A Fast Response Ultra Low Dropout Linear Regulators

March 2004
LP3853/LP3856
3A Fast Response Ultra Low Dropout Linear Regulators
General Description
The LP3853/LP3856 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 LP3853/LP3856
are developed on a CMOS process which allows low quies-
cent current operation independent of output load current.
This CMOS process also allows the LP3853/LP3856 to op-
erate under extremely low dropout conditions.
Dropout Voltage: Ultra low dropout voltage; typically 39mV
at 300mA load current and 390mV at 3A load current.
Ground Pin Current: Typically 4mA at 3A 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 Stable with selected ceramic capacitors
n Low ground pin current
n Load regulation of 0.08%
n 10nA quiescent current in shutdown mode
n Guaranteed output current of 3A DC
n Available in TO-263 and TO-220 packages
n Output voltage accuracy ± 1.5%
n Error flag indicates output status
n Sense option improves load regulation
n Overtemperature/overcurrent protection
n −40˚C to +125˚C junction temperature range
Applications
n Microprocessor power supplies
n Stable with ceramic output capacitors
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
20030901
**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 Application Hints
for more information.
© 2004 National Semiconductor Corporation DS200309
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