Patent ID: 11929684
Assignee: SHANGHAI BRIGHT POWER SEMICONDUCTOR CO., LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 10:
11. The control circuit of claim 8, wherein the oscillator considers the supposed instant of arrival of the rising or falling edge of the square wave signal as the first turn-on instant based on the currently set frequency, and checks whether the secondary-side transistor switch control signal is asserted at an instant prior to the first turn-on instant, the oscillator comprising:
a frequency setting current source configured to generate a frequency setting current based on the amplified error signal;
a frequency setting capacitor comprising a first terminal for receiving the frequency setting current and a second terminal connected to a reference ground;
a discharge branch connected in parallel with the frequency setting capacitor, the discharge branch controlled by an enable signal to start or stop discharging, the discharge branch making up a discharge loop with a capacitive time constant together with the frequency setting capacitor;
a first hysteresis inverter comprising an input connected to the first terminal of the frequency setting capacitor;
an edge detection circuit comprising an input connected to an output of the first hysteresis inverter and an output for providing the primary-side transistor switch control signal; and
an enable NOR gate comprising a first input for receiving the secondary-side transistor switch control signal, a second input connected to the output of the first hysteresis inverter and an output for presenting the enable signal.