Track and hold circuit and method

摘要

A track and hold circuit has a main transistor for which the gate voltage is provided by a buffer circuit which is supplied with a different voltage supply than the circuit of the main transistor. This avoids the need for a bootstrap circuit.

主权项

1. A track and hold circuit, comprising:
a main transistor between an input and an output of the circuit, wherein the main transistor is part of an integrated circuit supplied by a first set of voltage rails which form a digital core supply; a storage capacitor for storing the output voltage during a hold phase during which the main transistor is turned off; and a buffer circuit for generating a gate voltage for turning on the main transistor during a track phase, wherein the buffer circuit includes at least one transistor and is adapted to derive a gate voltage based on one of the input voltage and the output voltage of the circuit and a voltage step with respect to the input voltage or the output voltage, wherein the buffer circuit is supplied by a second set of voltage rails which form an analogue supply and with a greater voltage swing than the first set of voltage rails.