Patent ID: 7804337
Filing Date: 2010-09-28
Classification: G11C,H03M

Abstract:
1. 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 hold terminal that is adapted to provide the hold signal; a track terminal that is adapted to provide the track signal; a first differential input circuit having a plurality of transistors, wherein the first differential input circuit is adapted to receive the track signal and the hold signal and is coupled to the first and second output nodes; a second differential input circuit having a plurality of transistors, wherein the differential input circuit is adapted to receive the track signal and the hold signal and is coupled to the first and second output nodes; and a peaking circuit that is coupled to the first and second differential input circuits, wherein the peaking circuit causes the current through at least one of the transistors to exceed a threshold for a predetermined period when the track-and-hold circuit transitions from track to hold; 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.