Patent ID: 11870350
Assignee: APPULSE POWER INC.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 8:
9. A method, comprising:
a controller circuit, in a switched-mode power converter, generating a fixed switching frequency pulse width modulation (PWM) signal with an incrementing duty-ratio value to control a main-switch when the controller circuit is configured in a first mode of startup operation;
based on a first comparison of a power converter output voltage with a reference voltage, the controller circuit switching to a second mode of startup operation that is a quasi-resonant valley reduction mode of operation;
during the second mode of startup operation, the controller circuit decreasing an off-time of the duty-ratio value by reducing a number of quasi-resonant valleys detected in one or more off-times of the main-switch in one or more respective main-switch switching periods; and
the controller circuit entering a normal mode of operation based on a second comparison that determines that a difference between the reference voltage and an indication of the power converter output voltage is not greater than a predefined threshold voltage.