Patent ID: 7804336

Claim:
A track-and-hold circuit that is adapted to track an analog input signal and hold a sampled voltage of the analog input signal at a sampling instant for processing by other circuitry, in response to a track signal that alternates with a hold signal, the track-and-hold circuit comprising: a bi-directional current source that sources and sinks current through a first output node and a second output node, wherein the bi-directional current source includes: a differential input circuit that is adapted to receive the track signal and the hold signal and that is coupled to the first and second output nodes; an RC network that is coupled to the differential input circuit, wherein the RC network receives the analog input signal and is scaled to change the location of a zero to reduce the signal-dependence of the sampling instant; a unity gain amplifier that is coupled to first and second output nodes of the bi-directional current source and that receives the analog input signal; a resistor coupled to an output of the unity gain amplifier; and a capacitor coupled between the resistor and ground.