Patent ID: 7659789

Claim:
A signal modulation circuit for modulating a differential pulse width modulation signal, comprising: a first channel signal processing element having an input coupled for receiving a first channel of the differential signal, an output, and a control signal output; a second channel signal processing element having an input coupled for receiving a second channel of the differential signal, an output, and a control signal output; a first logic gate having a first input coupled to the output of said first channel signal processing element, a second input coupled to the output of said second channel signal processing element, and an output; a second logic gate having a first input coupled to the control signal output of said first channel signal processing element, a second input coupled to the control signal output of said second channel signal processing element, a third input coupled to the output of said first logic gate, and an output; a first switch having a first electrode coupled to the output of said first channel signal processing element, a second electrode coupled for transmitting a first channel of an output signal, and a control electrode coupled to the output of said second logic gate; and a second switch having a first electrode coupled to the output of said second channel signal processing element, a second electrode coupled for transmitting a second channel of the output signal, and a control electrode coupled to the output of said second logic gate.