NOT RECOMMENDED FOR NEW DESIGN USE AS431 AP431/AP431A ADJUSTABLE PRECISION SHUNT REGULATOR Description Pin Assignments The AP431 and AP431A are 3-terminal adjustable precision shunt (1) SOT25 (2) SO-8 (Top View) regulators with guaranteed temperature stability over the applicable (Top View) extended commercial temperature range. The output voltage may be 1 8 CATHODE REF NC 5 ANODE 1 set at any level greater than 2.495V (V ) up to 36V merely by REF ANODE 2 7 ANODE selecting two external resistors that act as a voltage divider network. NC 2 3 6 ANODE ANODE These devices have a typical output impedance of 0.2. Active output 4 5 NC NC CATHODE 3 4 REF circuitry provides very sharp turn-on characteristics, making these devices excellent improved replacements for Zener diodes in many applications. (3) SC59 (4) SC59R (Top View) (Top View) The precise (+/-) 1% reference voltage tolerance of the 1 CATHODE 1 REF AP431/AP431A make it possible in many applications to avoid the 3 ANODE 3 ANODE use of a variable resistor, consequently saving cost and eliminating CATHODE 2 REF 2 drift and reliability problems associated with it. (5) SOT23 (6) SOT23R Features (Top View) (Top View) Precision Reference Voltage REF 1 CATHODE 1 AP431: 2.495V 1% AP431A: 2.495V 0.5% 3 ANODE 3 ANODE Sink Current Capability: 200mA Minimum Cathode Current for Regulation: 300A CATHODE 2 REF 2 Equivalent Full-Range Temp Coefficient: 30ppm/C Fast Turn-On Response Low Dynamic Output Impedance: 0.2 (7) SOT89 (Top View) Programmable Output Voltage to 36V Low Output Noise Lead Free Packages: SOT25, SC59, SC59R, SOT89 and SO-8 Totally Lead-Free RoHS Compliant (Notes 1 & 2) SOT23, SOT23R, SOT25, SC59, SC59R, SO-8, SOT89: 3 1 2 Available in Green Molding Compound (No Br, Sb). See Anode Cathode Ordering Information REF Halogen and Antimony Free. Green Device (Note 3) Notes: 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant. 2. See NOT RECOMMENDED FOR NEW DESIGN USE AS431 AP431/AP431A Typical Applications Circuit V V IN OUT + + R1 C IN C OUT AP431 R2 V = (1 + R1/ R2) V OUT REF Precision Regulator Symbol Cathode (C) REF (R) Anode (A) Functional Block Diagram REF (R) + - V REF Anode (A) 2 of 17 September 2014 AP431/AP431A Diodes Incorporated www.diodes.com Document number: DS31002 Rev. 21 - 2 Cathode (C)