Patent ID: 8125803
Filing Date: 2012-02-28
Classification: H02M

Abstract:
1. A pulse width modulation signal generator for generating two pulse-width-modulation signals and a polarity signal on the basis of a control quantity, comprising: a polarity signal generator configured to generate the polarity signal with a first signal level indicating a first polarity, if the control quantity is larger than a predetermined threshold value, and to generate the polarity signal with a second signal level indicating a second polarity, if the control quantity is smaller than the predetermined threshold value; and a pulse width modulator configured to generate the first pulse-width-modulation signal such that a duty cycle of the first pulse-width-modulation signal increases substantially monotonically with an absolute value of a difference between the control quantity and the threshold value, and configured to generate the second pulse-width-modulation signal such that the second pulse-width-modulation signal is complementary with respect to the first pulse-width-modulation signal, except for a dead time, during which both the first pulse-width-modulation signal and the second pulse-width-modulation signal are inactive, wherein the pulse-width-modulation signal generator is configured to ensure, that the polarity signal remains unchanged as long as the first pulse-width-modulation signal is active.