APL431
Adjustable Precision Shunt Regulator
Features
General Description
The APL431 is a 3-terminal adjustable voltage refer-
ence with specified thermal stability over applicable
commercial temperature ranges. Output voltage may
be set to any value between Vref (2.5 V) and 20 V with
two external resistors (see Figure 2). When used
with an photocoupler, the APL431 is an ideal voltage
reference in isolated feedback circuits for 2.5V to 12V
switching-mode power supplies. This device has a
typical output impedance of 0.1Ω. Active output cir-
cuitry provides a very sharp turn-on characteristic,
making the APL431 excellent replacements for ze-
ner diodes in many applications, including on-board
regulation and adjustable power supplies.
•
•
Precise Reference Voltage to 2.500V
Guaranteed 0.5%, 1% or 2% Reference
Voltage Tolerance
•
•
•
•
Sink Current Capability, 1mA to 100mA
Quick Turn-on
Adjustable Output Voltage, VO = Vref to 20V
Low Operational Cathode Current, 250µA
Typical
•
•
0.1Ω Typical Output Impedance
SOT-23, SOT-23-5, SOT-89, SO-8, TO-92
and TO-92S Packages
NC
NC
ANODE
2
3
5
1
4
3
1
2
Applications
REF
CATHODE
REF ANODE CATHODE
SOT-23 (Top View)
SOT-23-5 (Top View)
•
•
•
Linear Regulators
Adjustable Power Supply
Switching Power Supply
1
2
3
CATHODE
ANODE
ANODE
NC
8
7
6
5
REF
ANODE
ANODE
NC
1
2
3
Symbol
4
REF
ANODE CATHODE
REF
Anode
Cathode
SOT-89 (Top View)
SO-8 (Top View)
Functional Diagram
3
2
1
CATHODE
ANODE
3
2
1
CATHODE
Cathode
ANODE
REF
+
REF
REF
_
Vref
TO-92 (Top View)
TO-92S (Top View)
Anode
ANPEC reserves the right to make changes to improve reliability or manufacturability without notice, and advise
customers to obtain the latest version of relevant information to verify before placing orders.
Copyright ANPEC Electronics Corp.
1
www.anpec.com.tw
Rev. C.1 - Jun., 2003