3A Fast Response Ultra Low Dropout Linear Regulators
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 devel-
oped on a CMOS process which allows low quiescent current
operation independent of output load current. This CMOS
process also allows the LP3853/LP3856 to operate under ex-
tremely 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).
Typical Application Circuits
**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.
© 2011 National Semiconductor Corporation
Ultra low dropout voltage
Stable with selected ceramic capacitors
Low ground pin current
Load regulation of 0.08%
10nA quiescent current in shutdown mode
Guaranteed output current of 3A DC
Available in TO-263 and TO-220 packages
Output voltage accuracy ± 1.5%
Error flag indicates output status
Sense option improves load regulation
−40°C to +125°C junction temperature range
Microprocessor power supplies
Stable with ceramic output capacitors
GTL, GTL+, BTL, and SSTL bus terminators
Power supplies for DSPs
High efficiency linear regulators
Other battery powered applications
March 4, 2011