POWER SUPPLY WITH CONTINUOUS SPREAD-SPECTRUM SWITCHING SIGNAL

摘要

A switched-mode power supply with reduced electromagnetic interference (EMI) is described. This switched-mode power supply includes a modulation circuit that continuously frequency modulates a control signal over a bandwidth associated with a spread-spectrum modulation signal. By frequency modulating the control signal in the switched-mode power supply, spectral content associated with a modulated switching signal is spread evenly over the bandwidth, thereby reducing the EMI.

主权项

1. A switched-mode power supply, comprising:
a control circuit configured to provide a control signal; a modulation circuit, electrically coupled to the control circuit, configured to provide a modulated switching signal by frequency modulating the control signal over a bandwidth using a spread-spectrum modulation signal so that spectral content associated with the modulated switching signal is spread over the bandwidth in the spread-spectrum modulation signal; and a power-supply circuit, electrically coupled to the modulation circuit, configured to perform power conversion to generate an output signal based on the modulated switching signal.