Patent ID: 7701194

Claim:
A system for detecting a direct current (DC) component of a pulse-width modulated (PWM) signal, the system comprising: a modulator that generates the PWM signal; and a DC detector that detects a DC component of the PWM signal as a function of a switching frequency of the PWM signal, wherein the DC detector includes: a counter that provides a first count value and a second count value, wherein the first count value characterizes the number of times that the PWM signal transitions from a first voltage to a second voltage in a predetermined amount of time, and wherein the second count value characterizes the number of times that the PWM signal transitions from the second voltage to the first voltage in the predetermined amount of time; and a threshold comparator that compares the first count value to a first threshold and compares the second count value to a second threshold to provide a report signal that indicates a level of the DC component of the PWM signal relative to at least one of the first and second thresholds.