The application belongs to the technical field of power supply, and particularly relates to a power supply output mode adjusting circuit based on a load state, which comprises a
voltage division sub-circuit, an input
signal of an input end of the
voltage division sub-circuit being a sine
signal, and an output
signal of an output end of the
voltage division sub-circuit being a chord signal with a certain angle difference from the sine signal; two-stage low-pass filter sub-circuits, an input signal of an input end of the two-stage low-pass filter sub-circuits being the sine signal, and an output of an output end of the two-stage low-pass filter sub-circuits being a
quadrature signal; a multiplier, an X input end of the multiplier inputting the
quadrature signal, a Y input end of the multiplier inputting the chord signal, and an output end of the multiplier outputting a voltage related to the
phase difference; a
comparator COMP1B, an input of a positive input end of the
comparator COMP1B being the voltage, an input of a negative input end of the
comparator COMP1B being a reference voltage Vref2, and an output end of the comparator COMP1B outputting a
control signal, the
control signal being used for controlling a feedback mode of a
switching power supply. The circuit has the
advantage of strong adaptability, can adjust the power supply output mode according to the load state, and improves the flexibility of the power supply output mode adjustment.