Semiconductor Components Industries, LLC

System General Corporation

Chuan-Chang Li

Wei-Hsuan Huang

Chien-Yuan Lin

Meng-Jen Tsai

Gwo-Hwa Wang

Ming-Chang Tsou

Ta-Yung Yang

A start-up circuit to discharge EMI filter is developed for power saving. It includes a detection circuit detecting a power source for generating a sample signal. A sample circuit is coupled to the detection circuit for generating a reset signal in response to the sample signal. The reset signal is utilized for discharging a stored voltage of the EMI filter.

Start-up circuit to discharge EMI filter for power saving of power supplies

A power supply with an open-loop protection according to the present invention comprises a transformer, a switch, a signal generation circuit, a feedback detection circuit, a brown-out detection circuit, and a delay circuit. The transformer receives an input voltage. The switch is coupled to the transformer for switching the transformer. The signal generation circuit generates a switching signal to control the switch. The feedback detection circuit generates a pull-high signal in response to a feedback signal of the power supply. The brown-out detection circuit generates a delay signal in response to the pull-high signal and the input voltage. The delay circuit counts a delay time in response to the delay signal for generating a disabling signal coupled to the signal generation circuit to latch the switching signal. The brown-out detection circuit is utilized to detect whether the input voltage is in the brown-out condition for determining whether the open-loop protection is executed.

Power supply with open-loop protection

A transistor gate driving circuit is developed for power saving. It includes a first high-side transistor, a second high-side transistor and a low-side transistor. A voltage clamp device is connected to the gate terminal of the first high-side transistor to limit the maximum output voltage. A detection circuit is coupled to detect a feedback signal of the power converter. The feedback signal is correlated to the output load of the power converter. The detection circuit will generate a disable signal in response to the level of the feedback signal. The disable signal is coupled to disable the second high-side transistor once the level of the feedback signal is lower than a threshold.

Transistor gate driving circuit with power saving of power converter

Growing community of inventors

Hsinchu, Taiwan

Chuan-Chang Li