Patent ID: 6819197
Filing Date: 2004-11-16
Classification: H03L

Abstract:
An apparatus for filtering a phase error signal, comprising:a first filter subcircuit receiving a phase error signal from a phase comparator and filtering the error signal with the first filter subcircuit when enabled; a second filter subcircuit receiving the phase error signal from the phase comparator and filtering the error signal with the second filter subcircuit when enabled; a first enable switch and a second enable switch which are activated in combination to control filtering of the error signal; a fast acquisition subcircuit including a fast acquisition enable switch for changing a charge pump current through at least one of the first and second filter subcircuits; and wherein the first filter subcircuit is enabled by activating a first combination of the first and second enable switches and the second filter subcircuit is enabled by activating a second combination of the first and second enable switches.