Patent ID: 7336110

Claim:
A dual differential sawtooth signal generator, comprising: a first sawtooth voltage generator having a first charge capacitor and configured to provide a positive going sawtooth output signal; a second sawtooth voltage generator having a first discharge capacitor and configured to provide a negative going sawtooth output signal; a comparator that is configured to compare the positive going sawtooth output signal with the negative going sawtooth output signal and that is configured to provide a comparator output signal; a phase frequency comparator that, in response to the comparator output signal, is configured to provide signals to control a dual charge pump that is configured to provide a feedback control source current to the positive going sawtooth generator for controlling the magnitude of the positive going sawtooth output signal and that is also configured to provide a feedback control sink current to the negative going sawtooth generator for controlling the magnitude of the negative going sawtooth output signal; and wherein the magnitudes of the feedback control source current and the feedback control sink current have the same absolute value.