AS2954
250 mA Low Drop Out Voltage Regulator
FEATURES
APPLICATIONS
• Output Accuracy 5V, 3.3V,@ 250mA Output
• Very Low Quiescent Current
• Battery Powered Systems
• Cordless Telephones
• Low Dropout Voltage
• Radio Control Systems
• Portable/Palm Top/Notebook Computers
• Portable Consumer Equipment
• Portable Instrumentation
• Automotive Electronics
• SMPS Post-Regulator
• Extremely Tight Load And Line Regulation
• Very Low Temperature Coefficient
• Current & Thermal Limiting
• Improved Replacement With Hight IOUT For LP2954 Sockets
• Voltage Reference
• Avionics
AS2954 Version Over LP2954
• Error Flag Warns Of Output Dropout
• Logic-Controlled Electronic Shutdown
• Output Programmable From 1.24V to 29V
• Input Can Withstand -20V Reverse Battery & +60 Positive Transient
PRODUCT DESCRIPTION
The AS2954 is a low power voltage regulator. This device is an excellent choice for use in battery-powered applications such as
cordless telephones, radio control systems, and portable computers. The AS2954 features very low quiescent current (75µA Typ.) and
very low dropout voltage. This includes a tight initial tolerance of 0.5% max and 1% max., and very low output temperature
coefficient, making the AS2954 useful as a low-power voltage reference. The key AS2954 features include protection against reversed
battery, fold-back current limiting, and automotive load dump protection (60V positive transient).
The error flag output feature is used as power-on reset for warning of a low output voltage, due to falling voltage input of batteries.
Another feature is the logic compatible shutdown input which enables the regulator to be switched on and off. The AS2954 is offered
in a 3-pin TO-92and TO-263 package compatible with other 5 volt regulators, in 8-Pin plastic, SO-8, (same pin out as AS2951), TO-
220 and TO-263.
The regulator output voltage (of the 8-pin) may be pin-strapped for a 5Vand 3.3V or programmed from 1.24V to 29V with an external
pair of resistors. Look for AS2951 for 150mA and LP2951 for 100mA applications.
PIN CONNECTIONS
TO-263-3 Package
AS2954
TO-263-5 Package
AS2954
8-Pin Surface Mount (S)
TO-220-3 Package
AS2954
TO-220-5 Package
SOT-223 Package
INPUT
OUTPUT
1
2
3
4
8
7
6
5
SENSE
FEEDBACK
5V, 3.3V TAP
ERROR
AS2954
AS2954
SHUTDOWN
GND
AS2954
1
2
3
1
2
3
1
2
3
4
5
1)
INPUT
1)
INPUT
2) OUTPUT
OUTPUT
GND
2)
3)
4)
5)
3)
4)
5)
GND
SHUTDOWN
ERROR
GND
V
V
Top View
TO-92 (N)
IN
OUT
SHUTDOWN
ERROR
Front View
V
VIN
VOUT
ADJ
1
VIN
2
3
V
1
2
3 4
5
2
1
3
Top View
Top View
GND
OUT
Front View
Front View
OUTPUT
INPUT
GND
Bottom View
Rev.9/29/00
SIPEX [ SIPEX CORPORATION ]
