page_title: TL431
hierarchical_section_title: TL431
caption_attribution_description: English: Equivalent (abstraction level) schematic of the TL431. Note that actual, transistor-level schematic does not contain neither a 2.5V source (it's actually a 1.2V bandgap), nor a traditional balanced-input opamp (it's a current bridge differential circuit).
context_page_description: The TL431 is a three-terminal adjustable precision shunt voltage regulator integrated circuit. With the use of an external voltage divider, TL431 can regulate voltages ranging from 2.5 to 36 V, at currents up 100 mA. Typical initial deviation of reference voltage from nominal 2.495 V level is measured in millivolts, maximum worst-case deviation is measured in tens of millivolts. The circuit can control power transistors directly; combinations of TL431 with power MOS transistors are employed in high efficiency, very low dropout linear regulators. The TL431 is the de facto industry standard error amplifier circuit for switched-mode power supplies with optoelectronic coupling of input and output networks.
  The TL431 was introduced by Texas Instruments in 1977. In the 21st century the original TL431 remains in production along with a multitude of clones and derivatives. These functionally similar circuits may differ considerably in die size and layout, precision and speed characteristics, minimal operating currents and safe operating areas.
context_section_description: The TL431 is a three-terminal adjustable precision shunt voltage regulator integrated circuit. With the use of an external voltage divider, TL431 can regulate voltages ranging from 2.5 to 36 V, at currents up 100 mA. Typical initial deviation of reference voltage from nominal 2.495 V level is measured in millivolts, maximum worst-case deviation is measured in tens of millivolts. The circuit can control power transistors directly; combinations of TL431 with power MOS transistors are employed in high efficiency, very low dropout linear regulators. The TL431 is the de facto industry standard error amplifier circuit for switched-mode power supplies with optoelectronic coupling of input and output networks.
  The TL431 was introduced by Texas Instruments in 1977. In the 21st century the original TL431 remains in production along with a multitude of clones and derivatives (TL432, ATL431, KA431, LM431, TS431, 142ЕН19 and others). These functionally similar circuits may differ considerably in die size and layout, precision and speed characteristics, minimal operating currents and safe operating areas.
caption: Equivalent (functional level) schematic
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