Patent ID: 8203363
Filing Date: 2012-06-19
Classification: G01R

Abstract:
1. A frequency detection apparatus, comprising: a frequency conversion circuit, for receiving an input clock, and generating an analog signal corresponding to a frequency of the input clock based on the frequency of the input clock; an analog conversion circuit, coupled to the frequency conversion circuit, for receiving the analog signal and generating a plurality of discriminating signals, each corresponding to the frequency of the input clock based on the analog signal, wherein each discriminating signal represents a frequency interval of the input clock; and wherein the analog conversion circuit comprises a plurality of comparators, each comparator having a first input end, a second input end, and an output end, wherein the first input end receives the analog signal, the second input end receives a reference voltage, each comparator compares the analog signal with the respective reference voltage to generate the one of the discriminating signals, and outputs the discriminating signal from the output end, wherein the reference voltage received by each comparator is a different reference voltage than the reference voltages received by the other comparators.