Patent ID: 8194425
Filing Date: 2012-06-05
Classification: H03K

Abstract:
1. A frequency modulation device comprising: a counter for using a first clock signal having a predetermined cycle and generating at least one first signal having a cycle of an integer times the predetermined cycle of the first clock signal; a latch unit, configured to receive the first signal and a control signal having a varying cycle, for detecting the first signal at a reference time according to the varying cycle of the control signal and for generating a second signal corresponding to a level of the detected first signal; a reference signal generator for generating a first reference signal having at least two different levels according to the second signal; and a pulse width modulation (PWM) oscillator for generating an oscillator signal that increases with a first slope and decreases with a second slope between the first reference signal and a second reference signal, wherein the second reference signal has a level that is different from that of the first reference signal.