US 2015/0145490 A1 · CONTROL METHOD AND CONTROL CIRCUIT FOR SWITCHING POWER SUPPLY

Abstract

In one embodiment, a method of controlling a switching power supply can include: (i) generating an ideal on time signal according to an input voltage and an output voltage of the switching power supply; (ii) generating a ripple voltage signal having a predetermined constant value when a power switch of the switching power supply is on, and a linearly decreasing value when the power switch is off; (iii) generating a regulating voltage signal according to an output voltage sense signal and the ripple voltage signal; (iv) generating a regulating control signal by comparing the regulating voltage signal against a first reference signal; (v) generating an on time control signal according to the regulating control signal and the ideal on time signal; and (vi) generating a driving signal according to the on time control signal for driving the power switch.

Claims14

Dependent claims

A method of controlling a switching power supply, the method comprising:

a) generating an ideal on time signal according to an input voltage and an output voltage of said switching power supply;
b) generating a ripple voltage signal having a predetermined constant value when a power switch of said switching power supply is on, and a linearly decreasing value when said power switch is off;
c) generating a regulating voltage signal according to an output voltage sense signal and said ripple voltage signal;
d) generating a regulating control signal by comparing said regulating voltage signal against a first reference signal;
e) generating an on time control signal according to said regulating control signal and said ideal on time signal;
and
f) generating a driving signal according to said on time control signal for driving said power switch.

4 more elements

A control circuit for a switching power supply, comprising:

a) an on time generating circuit configured to generate an ideal on time signal according to an input voltage and an output voltage of said switching power supply;
b) a ripple generating circuit configured to generate a ripple voltage signal having a predetermined constant value when a power switch of said switching power supply is on, and a linearly decreasing value when said power switch is off;
c) a sampling circuit configured to sense said output voltage of said switching power supply, and to generate an output voltage sense signal;
d) a comparison circuit configured to generate a regulating voltage signal according to said output voltage sense signal and said ripple voltage signal, and to generate a regulating control signal by a comparison of said regulating voltage signal against a first reference signal;
and
e) a driving circuit configured to generate an on time control signal according to said regulating control signal and said ideal on time signal, and to generate a driving signal for said power switch according to said on time control signal.

3 more elements

Dependencies are inferred from the claim text.

Control method and control circuit for switching power supply

Life of this patent

Control method and control circuit for switching power supply

Life of this patent

Abstract

Claims14