The LP2950 and LP2951 are micropower voltage regulators that are 
specifically designed to maintain proper regulation with an
extremely
low input−to−output voltage differential. These devices feature a
very
low quiescent bias current of 75 A and are capable of supplying
output currents in excess of 100 mA. Internal current and thermal
limiting protection is provided.
The LP2951 has three additional features. The first is the Error
Output that can be used to signal external circuitry of an out of
regulation condition, or as a microprocessor power−on reset. The
second feature allows the output voltage to be preset to 5.0 V, 3.3
V or
3.0 V output (depending on the version) or programmed from 1.25 V
to 29 V. It consists of a pinned out resistor divider along with
direct
access to the Error Amplifier feedback input. The third feature is
a
Shutdown input that allows a logic level signal to turn−off or
turn−on
the regulator output.
Due to the low input−to−output voltage differential and bias
current
specifications, these devices are ideally suited for battery
powered
computer, consumer, and industrial equipment where an extension of
useful battery life is desirable. The LP2950 is available in the
three
pin case 29 and DPAK packages, and the LP2951 is available in the
eight pin dual−in−line, SOIC−8 and Micro8 surface mount packages.
The ‘A’ suffix devices feature an initial output voltage tolerance
±0.5%.
Features 
• Pb−Free Packages are Available
• Low Quiescent Bias Current of 75 µA
• Low Input−to−Output Voltage Differential of 50 mV at 100 µA and
380 mV at 100 mA
• 5.0 V, 3.3 V or 3.0 V ±0.5% Allows Use as a Regulator or
Reference
• Extremely Tight Line and Load Regulation
• Requires Only a 1.0 F Output Capacitor for Stability
• Internal Current and Thermal Limiting
• NCV Prefix for Automotive and Other Applications Requiring Site
and Control Changes LP2951
Additional Features
• Error Output Signals an Out of Regulation Condition
• Output Programmable from 1.25 V to 29 V
• Logic Level Shutdown Input
