Patent ID: 8258798
Filing Date: 2012-09-04
Classification: G01R

Abstract:
1. A method of measuring a duty cycle of a first clock signal comprising: charging a capacitor to a first voltage level; discharging the capacitor to a second voltage level by applying a reference clock signal; measuring a first number of clock cycles of said reference clock signal elapsed during the discharging of said capacitor from the first voltage level to the second voltage level with application of the reference clock signal; recharging said capacitor to the first voltage level; discharging said capacitor to the second voltage level by applying a first clock signal of an unknown duty cycle; measuring a second number of clock cycles of said first clock signal elapsed during the discharging of said capacitor from the first voltage level to the second voltage level with application of the first clock signal; and calculating said duty cycle of said first clock signal from the first number of clock cycles and the second number of clock cycles.