SPX3940/41/42
1A Low Drop Out Voltage Regulator
with Shutdown
(PRELIMINARY INFORMATION)
FEATURES
APPLICATIONS
• Output Accuracy 3.3V, @ 1A Output
• Very Low Quiescent Current
• Low Dropout Voltage
• Battery Powered Systems
• Cordless Telephones
• 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
• Error Flag Warns Of Output Dropout
• Voltage Reference
PRODUCT DESCRIPTION
The SPX3940/41/42 is a low power voltage regulator. This device is an excellent choice for battery-powered applications such as
cordless telephones, radio control systems and portable computers. The SPX3940/41/42 features very low quiescent current (100µA
Typ.) and very low dropout voltage. This includes a tight initial tolerance of 1% max and 2% max., and very low output temperature
coefficient, making the SPX3940/41/42 useful as a low-power voltage reference.
The error flag output feature is used as power-on reset for warning of a low output voltage, due to a falling voltage input of batteries.
Another feature is the logic-compatible shutdown input which enables the regulator to be switched on and off. The SPX3940/41/42 is
offered in 3-pin and 5-pin TO-220 package SOT-223, and surface mount TO-263 packages.
The regulator output voltage (of the 8-pin SO-8 and 5-pin TO-220 & TO-263) may be pin-strapped for a 3.3V or programmed from
1.24V to 29V with an external pair of resistors.
PIN CONNECTIONS
SOT-223 Package
TO-220 Package
SPX3940
TO-263-5 Package
SPX3941/42
TO-220-5 Package
VOUT
SPX3940
GND/ ADJ
VIN
1
2
3
Five Lead Package Pin Functions:
SPX3941/42
SPX3941
1) ERROR
INPUT
GND
SPX3942
ADJUST
GND/
ADJ
V
V
IN
OUT
Front View
SHUTDOWN
2)
3)
4)
5)
Front View
TO-252 Package
GND
OUTPUT
INPUT
1
2 3 4
5
TO-263Package
SHUTDOWN OUTPUT
Top View
1 2 3 4 5
3
2
1
VOUT
3
2
1
VOUT
Top View
ADJ/GND
VIN
GND/ ADJ
V IN
Front View
Front View
Rev. 12/19/00