Patent ID: 8575970

Claim:
A track and hold circuit, comprising: a gain control circuit, arranged to provide a gain value upon an input signal according to a set of first signals, the gain control circuit comprises: a first resistor-based network, arranged to selectively provide a first resistance between a first signal receiving terminal receiving the input signal and a first input terminal of an operational amplifier according to the set of first signals; and a second resistor-based network, arranged to selectively provide a second resistance between the first input terminal of the operational amplifier and a first output terminal of the operational amplifier according to the set of first signals; the operational amplifier, arranged to generate an output signal according to the input signal and the gain value; and a first capacitor, arranged to hold the output signal between the first input terminal and the first output terminal of the operational amplifier; wherein when the track and hold circuit is operating, a first terminal of the first capacitor is consistently coupled to the first input terminal of the operational amplifier, and a second terminal of the first capacitor is consistently coupled to the first output terminal of the operational amplifier; and the first resistor-based network and the second resistor-based network are driven by a set of second signals when the track and hold circuit is operating, and the set of second signals are synchronized according to a specific signal of the set of first signals.