AME, Inc.
AME431B
Adjustable Precision Shunt Regulator
n
General Description
The AME431B series ICs are 3-terminal adjustable
shunt regulator with guaranteed temperature stability over
a full operation range. These ICs feature sharp turn-on
characteristics, low temperature coefficient and low out-
put impendance, which make them ideal substitutes for
Zener diodes in applications such as switching power
supply, charger and other adjustable regulators.
The reference is set to 1.24V for AME431Bxxxxx12 and
2.5V for AME431Bxxxxx25. The output voltage can be
set to 1.24V to 16V for V
REF
=1.24V part type and 2.5 to
36V for V
REF
=2.5V part type with two external resistors.
The AME431B precision reference is offered in two ref-
erence tolerance: 0.5% and 1.0%
The 5 main packages have low thermal impendance
which allows operation over a wide range of -40
o
C t o
+125
o
C.
n
Functional Block Diagram
V+ (Cathode)
REF
V
REF
GND (Anode)
n
Features
l
Very accurate reference voltage : 0.15% typical
l
High stability under capacitive load
l
Low temperature deviation: 4.5mV typical
l
Low equivalent full-range temperature coefficient
with 20PPM/
o
C typical
l
Low dynamic output resistance: 0.2Ω typical
l
Sink current capacity from 1mA to 100mA
l
Low output noise
l
Available in 5 packages: TO-92, SOT-23-3,
SOT-89, SO-8 and SOT-25
n
Applications
l
Adjustable power supplies
l
Linear regulators
l
Battery operated computer
l
Portable electronics
l
l
l
l
l
Instrumentation
Switching power supply
Mother board
LCD monitor
Note book computer
1
AME [ ANALOG MICROELECTRONICS ]
