Patent ID: 7049866

Claim:
A signal synthesizer comprising a loop filter connected between a charge pump and an oscillator of the signal synthesizer to accumulate charge from the charge pump and generate at least a first control signal for the oscillator, the loop filter comprising: a damping capacitor connected at a first node to a resistor connected to the oscillator to generate the first control signal for the oscillator; a matching capacitor; sensing-and-canceling circuitry connected to the damping capacitor and to the matching capacitor and adapted to (1) drive a voltage across the matching capacitor to match a first reference voltage applied to an input of the sensing-and-canceling circuitry and (2) generate, based on a first current associated with driving the voltage across the matching capacitor, a second current applied to the damping capacitor to compensate for leakage current in the damping capacitor; transconductor circuitry connected to the first node; and a transconductor capacitor connected to the transconductor circuitry and the oscillator to generate a second control signal for the oscillator.