EMI reduction of voltage inverters by way of controlled randomized modulation of oscillating signals

摘要

A switching control circuit for a voltage inverter generates an oscillating signal that causes reduced electromagnetic interference by the voltage inverter by way of modulating the frequency of the oscillating signal within a specified frequency range. A randomized signal generator creates a randomized signal, which is then used to drive a frequency range converter that is employed to produce a frequency modulation signal. The current state of the frequency modulation signal is based on the current state of the randomized signal, with the frequency range converter limiting the current state of the frequency modulation signal so that the oscillating signal will only operate within the specified frequency range. A variable frequency oscillator then generates the oscillating signal whose frequency is based on the current state of the frequency modulation signal. The oscillating signal is then inverted to produce an inverted oscillating signal, with both the oscillating signal and the inverted oscillating signal then driving the voltage inverter.