Predictive synchronous rectification controller, switching power converter with predictive synchronous rectification controller and controlling method thereof
AssigneeNiko Semiconductor Co., Ltd.
InventorTa-Ching Hsu
Life of this patent
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Abstract
A predictive synchronous rectification controller for controlling at least one synchronous rectification switch is provided. The synchronous rectification controller has a ramp generator, a peak sampling unit, and an output control unit. The ramp generator receives a synchronous signal and generates a ramp signal accordingly. The peak sampling unit generates a predicted reference voltage signal by retrieving a peak voltage of the ramp signal. The output control unit compares the ramp signal with the predicted reference voltage signal to generate a synchronous rectification control signal to control a conducting state of the switch.
Claims15
A secondary-side synchronous rectification controller for controlling at least one synchronous rectification switch, comprising:
- a ramp generator, for receiving a synchronous signal and generating a ramp signal according to the synchronous signal;
- a peak sampling unit, for retrieving a peak voltage of the ramp signal and generating a predicted reference voltage signal, which gradually declines in voltage level, and the peak sampling unit comprising:
- a maintaining capacitor, for receiving the ramp signal, and outputting the predicted reference voltage signal from a high-voltage side thereof;
- a discharging unit for discharging electrical charges stored in the maintaining capacitor;
- and
- a reference bias voltage source, for lowering a stored voltage of the maintaining capacitor so as to have a maximum stored voltage smaller than the peak voltage of the ramp signal;
- and
- an output control unit, for comparing the ramp signal with the predicted reference voltage signal and generating a dead time control signal to control a conducting state of the synchronous rectification switch.
A power converting circuit with secondary-side synchronous rectification, comprising:
- a transformer, having a primary-side winding and a secondary-side winding;
- a synchronous rectification switch, coupled to the secondary-side winding;
- and
- a secondary-side synchronous rectification controller, for controlling the synchronous rectification switch, and the synchronous rectification switch comprising:
- a ramp generator, for receiving a synchronous signal and generating a ramp signal according to the synchronous signal;
- a peak sampling unit, for retrieving a peak voltage of the ramp signal and generating a predicted reference voltage signal, which gradually declines in voltage level, and the peak sampling unit comprising:
- a maintaining capacitor, for receiving the ramp signal, and outputting the predicted reference voltage signal from a high-voltage side thereof;
- a discharging unit for discharging electrical charges stored in the maintaining capacitor;
- and
- a reference bias voltage source, for lowering a stored voltage of the maintaining capacitor so as to have a maximum stored voltage smaller than the peak voltage of the ramp signal;
- and
- an output control unit, for comparing the ramp signal and the predicted reference voltage signal and generating a dead time control signal to control a conducting state of the synchronous rectification switch.
Dependencies are inferred from the claim text.