Patent ID: 7616046

Claim:
A system for generating a PWM output voltage signal for a load, wherein the system comprises: a first half bridge and a second half bridge, wherein the first half bridge comprises a series connection of a first switch and a second switch and wherein the second half bridge comprises a series connection of a third switch and a fourth switch, wherein the first half bridge and the second half bridge are connected between a first rail and a second rail for supplying a DC voltage over the first half bridge and the second half bridge, and wherein, in use, the load is connected between a first junction of the first switch and the second switch and a second junction of the third switch and the fourth switch, and a control unit configured for generating at least a first PWM switch-signal for switching the switches of the first half bridge and at least a second PWM switch-signal for switching the switches of the second half bridge, wherein the control unit is further configured for varying pulse widths and/or phases of the first and second PWM switch-signals relative to each other for varying a pulse width of the PWM output voltage signal, wherein, for generating a zero PWM output voltage signal, the control unit configured to generate the first PWM switch-signal and the second PWM switch-signal such that the respective pulse width and phase of the first PWM switch-signal and the respective pulse width and phase of the second PWM switch-signal are, at least substantially, equal.