The IC431 is a voltage regulator chip with four pins. The functions of each pin are described as follows:
1. Vin (pin 1) : Input voltage pin. This pin is used to connect the positive terminal of the input power supply. The voltage of the input power supply is usually between 3V and 40V.
2.GND (pin 2) : ground pin. This pin is connected to the negative terminal of the power supply and is used to establish a current loop.
3. Vout (pin 3) : Output voltage pin. The pin provides an adjusted output voltage. The output voltage can be adjusted from 0V to Vin, set by an external resistor.
4. Adj (pin 4) : Adjust pin. This pin is used for fine regulation of the output voltage. By connecting a resistor to this pin, the exact value of the output voltage can be manually adjusted. If fine adjustment is not required, this pin can be connected directly to the ground pin.
Please note that the above information is for reference only and specific pin functions may vary by chip version or manufacturer. Please refer to the data sheet of the IC431 for accurate pin function information before use.
Literally facing up, the pins from left to right are 1 pin R sampling end, 2 pin A grounding end, 3 pin K control end.