Data Sheet
ADJUSTABLE PRECISION SHUNT REGULATORS
General Description
The AS431 series ICs are three-terminal adjustable
shunt regulators with guaranteed thermal stability over
a full operation range. These ICs feature sharp turn-on
characteristics, low temperature coefficient and low
output impedance, which make them ideal substitutes
for Zener diodes in applications such as switching
power supply, charger and other adjustable regulators.
The output voltage of these ICs can be set to any value
between V
REF
(2.5V) and the maximum cathode volt-
age (36V).
The AS431 precision reference is offered in two band-
gap tolerance: 0.4% and 0.8%.
These ICs are available in 4 Packages: TO-92, SOT-23-
3, SOT-23-5 and SOT-89 .
AS431
Features
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Programmable Precise Output Voltage from 2.5V
to 36V
Very Accurate Reference Voltage: 0.15% Typical
High Stability under Capacitive Load
Low Temperature Deviation: 4.5mV Typical
Low Equivalent Full-range Temperature Coeffi-
cient with 20PPM/
o
C Typical
Low Dynamic Output Resistance: 0.15Ω Typical
Sink Current Capacity from 1mA to 100 mA
Low Output Noise
Wide Operating Range of -40 to 125
o
C
Applications
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Charger
Voltage Adapter
Switching Power Supply
Graphic Card
Precision Voltage Reference
SOT-89
TO-92
SOT-23-3
SOT-23-5
Figure 1. Package Types of AS431
Nov. 2005 Rev. 1. 1
1
BCD Semiconductor Manufacturing Limited