How to calculate the voltage divider resistance of the 431 chip, a voltage reference source for a flyback switching power supply?

Knight97538

How to calculate the voltage divider resistance of the 431 chip, a voltage reference source for a flyback switching power supply? [Copy link]

Could any teacher help me and tell me how to calculate the voltage divider resistor of the 431 chip, the voltage reference source of the flyback switching power supply?

maychang

In this figure, the two voltage-dividing resistors R1 and R2 of TL431 should ensure that when the Vo terminal outputs the rated voltage, the Ref pin of TL431 is divided into 2.5V voltage.