Advanced
Monolithic
Systems
LP2950/LP2951
100mA LOW DROPOUT VOLTAGE REGULATOR
FEATURES
APPLICATIONS
· 5V, 3.3V, and 3V Versions at 100mA Output Current
· High Accuracy Output Voltage
· Extremely Low Quiescent Current
· Battery Powered Systems
· Portable Consumer Equipment
· Cordless Telephones
· Low Dropout Voltage
· Extremely Tight Load and Line Regulation
· Very Low Temperature Coefficient
· Portable (Notebook) Computers
· Portable Instrumentation
· Radio Control Systems
· Automotive Electronics
· Avionics
· Current and Thermal Limiting
· Needs Minimum Capacitance (1mF) for Stability
· Unregulated DC Positive Transients 60V
ADDITIONAL FEATURES (LP2951 ONLY)
· 1.24V to 29V Programmable Output
· Error Flag Warning of Voltage Output Dropout
· Logic Controlled Electronic Shutdown
· Low-Power Voltage Reference
GENERAL DESCRIPTION
The LP2950 and LP2951 are micropower voltage regulators ideally suited for use in battery-powered systems. These devices
feature very low quiescent current (typ.75µA), and very low dropout voltage (typ.45mV at light loads and 380mV at 100mA)
thus prolonging battery life. The quiescent current increases only slightly in dropout. The LP2950/LP2951 has positive
transient protection up to 60V and can survive unregulated input transient up to 20V below ground.
The LP2950 and LP2951 were designed to include a tight initial tolerance (typ. 0.5%), excellent load and line regulation (typ.
0.05%), and a very low output voltage temperature coefficient, making these devices useful as a low-power voltage reference.
The LP2950 is offered in the 3-pin TO-92 package. LP2951 is available in 8-pin plastic SOIC and DIP packages and offers
three major additional system features. An error flag output warns of a low output voltage, often due to failing batteries on
input. The LP2951 also features the logic-compatible shutdown input which enables the regulator to be switched on and off.
The LP2951 device may be pin-strapped for a 5V, 3.3V, or 3V output, or programmed from 1.24V to 29V with an external
pair of resistors.
ORDERING INFORMATION
PACKAGE TYPE
PIN CONNECTION
8L SOIC/ 8L PDIP
OPERATING
TEMP. RANGE
IND.
OUTPUT
SENSE
1
2
3
4
8
7
6
5
INPUT
TO-92
8 LEAD PDIP 8 LEAD SOIC
FEEDBACK
VTAP
LP2950ACN-X LP2951ACP-X LP2951ACS-X
SHUTDOWN
GROUND
LP2950CN-X
LP2951CP-X
LP2951CS-X
IND
ERROR
X = 3.3V, or 3V
Top View
TO-92
OUTPUT
GND
INPUT
Bottom View
Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140