Design of an AC-DC and DC-DC interleaved PWM controller for switching power supply

In this paper, the AC-DC and DC-DC interleaved control for power supply is proposed. In conventional power supplies, the front-stage AC-DC power-factor correction (PFC) converter and the rear-stage DC-DC converter are controlled independently; therefore, the current ripple on the DC-bus capacitor is uncontrolled and significant. One-cycle control is used in the front-stage AC-DC PFC converter such that it achieves high power factor and low current total harmonic distortion. The rear-stage DC-DC converter is controlled by current-mode modulator to regulate the output voltage. Moreover, the power switches of the front and the rear-stage converters are controlled with constant-frequency interleaved control; consequently, the current ripple on the DC-bus capacitor can be reduced, which leads to higher efficiency. The controller is implemented by the TSMC 0.25μm BCD CMOS 2.5/5/60 V process.