Disconnecting a time discrete circuit from a track-and-hold circuit in track mode

Abstract

A system and method for an improved analog front-end system is disclosed. By coupling a switch to the output of a track-and-hold circuit and to the input of a time-discrete circuit, such as an analog-to-digital converter, the time-discrete circuit can be disconnected from the track-and-hold circuit during the track mode of the track-and-hold circuit. This improved system reduces the load of the T/H circuit from the full input capacitance of the time-discrete circuit to the smaller parasitics of the switch thereby providing a T/H circuit with lower power consumption and smaller area while maintaining high speed and high accuracy. When the time-discrete circuit is an analog-to-digital converter, the system and method may also include a second shorted switch coupled between the first switch and the analog-to-digital converter for canceling the charge injection of the first switch and thereby enabling the analog-to-digital converter to convert an analog signal to a digital signal during the track phase of the track-and-hold circuit.