Patent ID: 6961400

Claim:
A frequency shift keyed (FSK) receiver capable of demodulating an incoming transmitted signal comprising: a phase-locked loop for receiving an oscillator reference signal having a reference frequency and generating a reference carrier frequency signal having a desired frequency, said phase-locked loop comprising: a phase detector having a first input for receiving said oscillator reference signal and a second input; and a frequency divider circuit for dividing an actual frequency of said reference carrier frequency signal by an adjustable integer value applied to a control input of said frequency divider circuit to thereby generate a feedback signal applied to said second input of said phase detector; a frequency discriminator that receives said incoming transmitted signal and said reference carrier frequency signal and generates a correction signal corresponding to a difference between a center frequency of said incoming transmitted signal and said actual frequency of said reference carrier frequency signal; and a delta-sigma modulator controlled by said correction signal operable to generate a sequence of integers having an average value over a defined time period, wherein said sequence of integers are applied to said control input of said frequency divider circuit.