LP38841-ADJ Datasheet, PDF (1/10 Pages) National Semiconductor (TI) – 0.8A Ultra Low Dropout Adjustable Linear Regulators Stable with Ceramic Output Capacitors

December 2006
LP38841-ADJ
0.8A Ultra Low Dropout Adjustable Linear Regulators
Stable with Ceramic Output Capacitors
General Description
The LP38841-ADJ 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 regulators, the CMOS archi-
tecture consumes extremely low quiescent current at any
output load current. The use of an N-MOS power transistor
results in wide bandwidth, yet minimum external capacitance
is required to maintain loop stability.
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 the PSOP package.
Dropout Voltage: 75 mV (typ) @ 0.8A load current.
Quiescent Current: 30 mA (typ) at full load.
Shutdown Current: 30 nA (typ) when S/D pin is low.
Precision Reference Voltage: 1.5% room temperature ac-
curacy.
Features
■ ^{Ideal for conversion from 1.8V or 1.5V inputs}
■ ^{Designed for use with low ESR ceramic capacitors}
■ ^{Ultra low dropout voltage (75mV @ 0.8A typ)}
■ ^{0.56V to 1.5V adjustable output range}
■ ^{Load regulation of 0.1%/A (typ)}
■ ^{30nA quiescent current in shutdown (typ)}
■ ^{Low ground pin current at all loads}
■ ^{Over temperature/over current protection}
■ ^{Available in 8 lead PSOP package}
■ ^{−40°C to +125°C junction temperature range}
■ ^{UVLO disables output when V}_BIAS ^{< 3.8V}
Applications
■ ^{ASIC Power Supplies In:}
- Desktops, Notebooks, and Graphics Cards, Servers
- Gaming Set Top Boxes, Printers and Copiers
■ ^{Server Core and I/O Supplies}
■ ^{DSP and FPGA Power Supplies}
■ ^{SMPS Post-Regulators}
Typical Application Circuit
* Minimum value required if Tantalum capacitor is used (see Application Hints).
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