LP4950C-5V_05 Datasheet, PDF (1/14 Pages) National Semiconductor (TI) – Adjustable Micropower Voltage Regulators

August 2005
LP4950C-5V and LP4951C
Adjustable Micropower Voltage Regulators
General Description
The LP4950C and LP4951C are micropower voltage regu-
lators with very low quiescent current (75µA typ.) and very
low dropout voltage (typ. 40mV at light loads and 380mV at
100mA). They are ideally suited for use in battery-powered
systems. Furthermore, the quiescent current of the
LP4950C/LP4951C increases only slightly in dropout, pro-
longing battery life.
The LP4950C in the popular 3-pin TO-92 package is pin
compatible with older 5V regulators. The 8-lead LP4951C is
available in a plastic surface mount package and offers
additional system functions.
One such feature is an error flag output which warns of a low
output voltage, often due to falling batteries on the input. It
may be used for a power-on reset. A second feature is the
logic-compatible shutdown input which enables the regulator
to be switched on and off. Also, the part may be pin-strapped
for a 5V output or programmed from 1.24V to 29V with an
external pair of resistors.
Careful design of the LP4950C/LP4951C has minimized all
contributions to the error budget. This includes a tight initial
tolerance (.5% typ.), extremely good load and line regulation
(.05% typ.) and a very low output voltage temperature coef-
ficient, making the part useful as a low-power voltage refer-
ence.
Features
n High accuracy 5V guaranteed 100mA output
n Extremely low quiescent current
n Low dropout voltage
n Extremely tight load and line regulation
n Very low temperature coefficient
n Use as Regulator or Reference
n Needs only 1µF for stability
n Current and Thermal Limiting
LP4951C versions only
n Error flag warns of output dropout
n Logic-controlled electronic shutdown
n Output programmable from 1.24 to 29V
Block Diagram and Typical Applications
LP4950C
LP4951C
20052825
20052801
© 2005 National Semiconductor Corporation DS200528
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