Monolithic Power Systems, Inc.
Isolated resonant converter with fixed output ripple

Abstract:

An isolated resonant converter has an analog comparator with hysteresis for generating a first ON/OFF signal, a digital isolator for outputting a second ON/OFF signal, an oscillator for providing a clock pulse signal with a frequency, and a primary pulse width modulator coupled to receive the clock pulse signal and the second ON/OFF signal. An output voltage of the isolated resonant converter is controlled by the analog comparator within a predefined range. The second ON/OFF signal is electrically isolated from the first ON/OFF signal. The primary pulse width modulator controls the switching of the isolated resonant converter in response to the clock pulse signal during the logic high state of the second ON/OFF signal and stops the switching of the isolated resonant converter during the logic low state of the second ON/OFF signal.