Creative Commons images are CC BY-NC-SA 3.0

Description: The TL431 is a three−terminal programmable shunt regulator diode. This monolithic IC voltage reference operates as a low temperature coefficient zener which is programmable from Vref to 36V with two external resistors. They exhibit a wide operating current range of 1.0mA to 100mA with a typical dynamic impedance of 0.22 ohms.

The characteristics of these references make them excellent replacements for zener diodes in many applications such as digital voltmeters, power supplies, and op-amp circuitry. The 2.5V reference makes it convenient to obtain a stable reference from 5.0V logic supplies, and since the TL431 operates as a shunt regulator, it can be used as either a positive or negative voltage reference.


  • Programmable Output Voltage to 36V
  • Voltage Reference Tolerance: ±0.4%, Typ @ 25°C (TL431B)
  • Low Dynamic Output Impedance, 0.22 ohms Typical
  • Sink Current Capability of 1.0mA to 100mA
  • Equivalent Full−Range Temperature Coefficient of 50 ppm/°C Typical
  • Temperature Compensated for Operation over Full Rated Operating Temperature Range
  • Low Output Noise Voltage
  • Pb and Halide−Free


Recommended Products

Customer Comments

  • You can find a free “tool” on the website that can calculate the resistor values for you (Excel sheet with a Macro).

    I created a quick screenshot of the tool in action which also includes a demo circuit of how to use it.

  • I need a stable reference voltage for a temperature monitor I am building using the TMP36 analog temp sensor and an Atmega328 self-built Arduino clone. Is something like this a good choice for that application?

    • Little late but could be useful: I did use this for a TMP36 project based around a PIC16F1828 and didn’t have any problems.

Customer Reviews

No reviews yet.