LP3883 Datasheet, PDF (1/12 Pages) National Semiconductor (TI) – 3A Fast-Response Ultra Low Dropout Linear Regulators

August 2003
LP3883
3A Fast-Response Ultra Low Dropout Linear Regulators
General Description
The LP3883 is a high-current, fast-response regulator which
can maintain output voltage regulation with minimum input to
output voltage drop. Fabricated on a CMOS process, the
device operates from two input voltages: Vbias provides
voltage to drive the gate of the N-MOS power transistor,
while Vin is the input voltage which supplies power to the
load. The use of an external bias rail allows the part to
operate from ultra low Vin voltages. Unlike bipolar regula-
tors, the CMOS architecture consumes extremely low quies-
cent current at any output load current. The use of an
N-MOS power transistor results in wide bandwidth, yet mini-
mum external capacitance is required to maintain loop sta-
bility.
The fast transient response of these devices makes them
suitable for use in powering DSP, Microcontroller Core volt-
ages and Switch Mode Power Supply post regulators. The
parts are available in TO-220 and TO-263 packages.
Dropout Voltage: 210 mV (typ) @ 3A load current.
Ground Pin Current: 3 mA (typ) at full load.
Shutdown Current: 60 nA (typ) when S/D pin is low.
Precision Output Voltage: 1.5% room temperature accu-
racy.
Features
n Ultra low dropout voltage (210 mV @ 3A typ)
n Low ground pin current
n Load regulation of 0.04%/A
n 60 nA typical quiescent current in shutdown
n 1.5% output accuracy (25˚C)
n TO-220, TO-263 packages
n Over temperature/over current protection
n −40˚C to +125˚C junction temperature range
Applications
n DSP Power Supplies
n Server Core and I/O Supplies
n Linear Power Supplies for PC Add-in-Cards
n Set-Top Box Power Supplies
n Microprocessor Power Supplies
n High Efficiency Linear Power Supplies
n SMPS Post-Regulators
Typical Application Circuit
At least 4.7 µF of input and output capacitance is required for stability.
Connection Diagrams
TO-220, Top View
20062402
© 2003 National Semiconductor Corporation DS200624
20062401
TO-263, Top View
20062403
www.national.com