®
SPX2950/SPX2951
150mA Low Dropout Voltage Regulator
TO-92 (N)
8-Pin Surface Mount (S)
FEATURES
1
2
3
1
2
8
7
INPUT
OUTPUT
SENSE
FEEDBACK
■ 5.0V and 3.3V at 150mA Output
■ Accurate: 0.5% for SPX2950A/SPX2951A
■ Very Low Quiescent Current
■ Low Dropout Voltage: 300mV at 150mA
■ Extremely Tight Load and Line Regulation
■ Very Low Temperature Coefficient
■ Current & Thermal Limiting
■ Need Only 1µF for Stability
■ Offered in TO-92 (SPX2950) and SOIC
(SPX2951)
SHUTDOWN
3
4
6
5
5V or 3.3V Output
ERROR
V
V
IN
GROUND
OUT
GROUND
SPX2950 Bottom View
SPX2951 Top View
Now Available in Lead Free Packaging
APPLICATIONS
■ Battery Powered Systems
■ Cordless Telephones
■ Radio Control Systems
■ Portable/Palm Top/Notebook Computers
■ Portable Consumer Equipment
■ Portable Instrumentation
■ Avionics
■ Direct Replacement for LP2950/LP2951
SPX2951 versions only
■ Error Flag Warns of Output Dropout
■ Logic-Controlled Electronic Shutdown
■ Output Programmable From 1.24 to 29V
■ SMPS Post-Regulator
■ Voltage Reference
■ Automotive Electronics
DESCRIPTION
The SPX2950 and SPX2951 are low power voltage regulators. These devices are an excellent choice for
use in battery-powered applications such as cordless telephones, radio control systems, and portable
computers. TheSPX2950andSPX2951featurelowquiescentcurrent andlowdropoutvoltage(typ.20mV
at100µAand300mVat150mA). Thisincludesatightinitialtoleranceof(0.5%forSPX2950A/SPX2951A),
extremely good load and line regulation (0.05% typ.), and very low output temperature coefficient (20ppm/
°C typ.), making the SPX2950/SPX2951 useful as a low-power voltage reference.
The error flag output feature is used as a power-on reset for warning of a low output voltage, due to a falling
voltage. The logic compatible shutdown feature enables the regulator to be switched ON and OFF. The
SPX2950 is offered in a 3-pin TO-92 package compatible with other 5.0V, 3.3V regulators. The SPX2951
is availiable in an 8-lead SOIC package.
UNREGULATED DC
5V
1
7
8
+
INPUT
FEEDBACK
OUTPUT
2
SENSE
180k
Ω
+
_
6
ERROR
FROM
CMOS OR
TTL
3
AMPLIFIER
330k
Ω
5V TAP
SHUTDOWN
+
60 mV
60k
Ω
1µF
.
5
______
ERROR
+
+
_
.
ERROR DETECTION
COMPARATOR
TO CMOS OR
TTL
1.23V
+
4
REFERENCE
GROUND
Block Diagram of SPX2951, 8 Lead 5V Version
DATE: 12/01/04
SPX2950/SPX2951 150mA Low Dropout Voltage Regulator
©Copyright 2004 Sipex Corporation
1