This part is a kind of semiconductor called TL431.
Function of this product has PROGRAMMABLE VOLTAGE REFERENCE.
Manufacturers : STMicroelectronics
Image and pinout :
Some of the text within the PDF file :
TL431 TL432 Programmable voltage reference Features ■ Adjustable output voltage: 2.5 to 36 V ■ Sink current capability: 1 to 100 mA ■ Typical output impedance: 0.22 Ω ■ 1% and 2% voltage precision ■ Automotive temp. range - 40 °C to +125 °C Applications ■ Power supply ■ Industrial ■ Automotive Description The TL431 and TL432 are programmable shunt voltage references with guaranteed temperature stability over the entire operating temperature range. The device temperature range is extended for the automotive version from -40 °C up to +125 °C. The output voltage can be set to any value between 2.5 and 36 V with two external resistors. The TL431 and TL432 operate with a wide current range from 1 to 100 mA with a typical dynamic impedance of 0.22 Ω. Datasheet − product [ ... ]