Digitally-synthesized loop filter circuit particularly useful for a phase locked loop

  • US 6,765,445 B2
  • Filed: 09/05/2003
  • Issued: 07/20/2004
  • Est. Priority Date: 07/10/2000
  • Status: Expired due to Term
First Claim
Patent Images

1. In a phase locked loop system, a digitally-synthesized loop filter circuit comprising:

  • a first circuit for providing a digital representation of a phase error signal of the phase locked loop;

    a second circuit responsive to the digital phase error signal, for generating a multi-bit accumulated digital phase error signal representing an accumulated value of successive values of the digital phase error signal; and

    a third circuit for generating an output signal corresponding to the accumulated digital phase error signal, said output signal useful for controlling an oscillator within the phase locked loop.

View all claims

    Thank you for your feedback