General Description
The APL431L is a 3-terminal low voltage adjustable precision reference with specified thermal stability over applicable commercial temperature ranges. Output voltage may be set to any value between Vref (1. 24 V) and 20 V with two external resistors (see Figure 2). When used with an photocoupler, the APL431L is an ideal voltage reference in isolated feedback circuits for 3V to 12V switching-mode power supplies. This device has a typical output impedance of 0.1Ω. Active output circuitry provides a very sharp turn-on characteristic,making the APL431L excellent replacements for zener diodes in many applications, including on-board regulation and adjustable power supplies.

Features
• Precise Reference Voltage to 1.24V
• Guaranteed 0.5% or 1% Reference Voltage Tolerance
• Sink Current Capability, 80uA to 100mA
• Quick Turn-on
• Adjustable Output Voltage, VO = VREF to 20V
• Low Operational Cathode Current, 80µA Typical
• 0.1Ω Typical Output Impedance
• SOT-23-3, SOT-23-5, TO-92 and SOT-89 Packages
• Lead Free Available (RoHS Compliant)

Applications
• Linear Regulators
• Adjustable Power Supply
• Switching Power Supply