Adjustable Precision Shunt Regulator(TL431/AP431 family)

The TL/AP431 family is 3-terminal adjustable precision shunt regulators with guaranteed temperature stability over the applicable extended commercial temperature range. The output voltage may be set at any level greater than 2.495V(VREF) up to 36V scarcely by selecting two external resistors that act as a voltage divider network. These devices have a typical output impedance of 0.2Ω.
Active output circuitry provides very sharp turn-on characteristics, making these devices excellent improved replacements for Zener diodes in many applications.
• The 431types feature an enhanced stability area with a very low load capacity requirement.

• It's offer an enhanced stability area and a higher Electromagnetic Interference (EMI) ruggedness, for example, for Switch Mode Power Supply (SMPS) applications.

• Designed for standard requirements and linear applications.

Features and benefits

• Three different reference voltage tolerances:

    Standard grade: 2 %

    A-Grade: 1 %

    B-Grade: 0.5 %

• Sink current capability: 1mA to 200mA

• Minimum cathode current for regulation: 300μA

• Equivalent full-range temp coefficient: 30 ppm/oC

• Fast turn-on response

• Low dynamic output impedance: 0.2Ω

• Programmable output voltage to 36v

• Low output noise.

• Typical temperature drift: 6 mV (in a range of 0 C up to 70 C)

Applications

• Shunt regulator

• Precision current limiter

• Precision constant current sink

• Isolated feedback loop for Switch Mode Power Supply (SMPS)

The output voltage may be set to any value between Vref (approximately 2.5 V) and 36 V with two external resistors. These devices have a typical output impedance of  0.2Ω . Active output circuitry provides a very sharp turn-on characteristic, making these devices excellent replacements for Zener diodes in many applications like on-board regulation, adjustable power supplies and switching power supplies.

Operating conditions
VKA cathode-anode voltage    .........................................................................Vref 36 V
IK cathode current                   ..........................................................................1 -100 mA

Reference Input Current Range .......……..............................………….…....... 10mA