Richtek Technology Corporation

Chen-Lin Hsu

Hung-Yu Cheng

Wan-Hsuan Yang

Chen-Pin Huang

Chia-Chun Li

Chia-Chun Lee

A switching power converter includes: a power stage circuit, including at least one transistor which is configured to operably switch an inductor to convert an input power to an output power; and an active EMI filter circuit, including at least one amplifier, wherein the at least one amplifier is configured to operably sense a noise input signal which is related to a switching noise caused by the switching of the power stage circuit, and amplify the noise input signal to generate a noise cancelling signal, wherein the noise cancelling signal is injected into an input node of the switching power converter, so as to suppress the switching noise and thus reducing EMI, wherein the input power is provided through the input node to the power stage circuit.

Switching power converter and active EMI filter circuit thereof

A switching power converter includes: a power stage circuit, including at least one transistor which is configured to operably switch an inductor to convert an input power to an output power; and an active EMI filter circuit, including at least one amplifier, wherein the at least one amplifier is configured to operably sense a noise input signal which is related to a switching noise caused by the switching of the power stage circuit, and amplify the noise input signal to generate a noise canceling signal, wherein the noise canceling signal is injected into an input node of the switching power converter, so as to suppress the switching noise and thus reducing EMI, wherein the input power is provided through the input node to the power stage circuit.

A spread spectrum switching power converter circuit includes: a power stage circuit which includes an inductor and a power switch and is configured to switch the power switch according to a switching signal having spread spectrum for power conversion; a variable frequency oscillator, which generates a spread spectrum clock signal according to a spread spectrum control signal; a spread spectrum control circuit, which generates the spread spectrum control signal according to a first clock signal and a second clock signal; and a pulse width modulation circuit, configured to generate the switching signal according to a feedback signal based on the spread spectrum clock signal. The spread spectrum control circuit generates the spread spectrum control signal by sampling and combining a periodic waveform and a random waveform. The random waveform is generated according to the first clock signal and the periodic waveform is generated according to the second clock signal.

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Taoyuan, Taiwan

Chen-Lin Hsu