General Description

The APL431 is a 3-terminal adjustable voltage reference 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 circuitry provides a very sharp turn-on characteristic, making the APL431 excellent replacements for zener diodes in many applications, including on-board regulation and adjustable power supplies.

Features

• 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

Applications

• Linear Regulators

• Adjustable Power Supply

• Switching Power Supply