Copyright  ANPEC Electronics Corp.
Rev. C.1 - Jun., 2003
APL431
www.anpec.com.tw1
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.
Adjustable Precision Shunt Regulator
Features General Description
Applications
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 V
ref
(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, V
O
= V
ref
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
• Linear Regulators
• Adjustable Power Supply
• Switching Power Supply
CathodeAnode
REF
Symbol
Functional Diagram
Vref
G2B
G5F
Cathode
REF
Anode
SOT-23 (Top View)
REF
ANODE
CATHODE
12
3
SOT-89 (Top View)
REF ANODE CATHODE
123
REF
ANODE
CATHODE3
2
1
TO-92 (Top View)
SO-8 (Top View)
REF
ANODE
CATHODE
ANODE
NC
ANODE
ANODE
NC
1
2
3
4
8
7
6
5
REF ANODE
NC NC
CATHODE
123
45
SOT-23-5 (Top View)
REF
ANODE
CATHODE3
2
1
TO-92S (Top View)