| 摘要 |
Noise reducing circuitry may be included in a pulse width modulation circuit. The pulse width modulation circuit may include a comparator adapted to receive an analog signal and a sawtooth signal and to compare such signals to generate a pulse width output. In general, the noise reducing circuitry may include a sawtooth signal generating circuit configured to generate a sawtooth signal including an up ramp and a sawtooth signal including a down ramp. A control circuit may be coupled to the sawtooth signal generating circuit for controlling the sawtooth signal generating circuit based on whether a relatively narrow or relatively wide pulse width is to be output by the pulse width modulation circuit. Methods for reducing noise in a pulse width modulation circuit may generally involve dynamically controlling a direction of ramp of a sawtooth signal that is to be input to the comparator of the pulse width modulation circuit. |
