Patent ID: 8803719
Filing Date: 2014-08-12
Classification: H03K

Abstract:
1. A sample and hold circuit, comprising: an input terminal configured to receive an input signal; an output terminal configured to provide an output signal; a control circuit configured to receive the input signal and the output signal, wherein based on the input signal and the output signal, the control circuit generates a digital signal, and wherein the digital signal is changed when the output signal is lower than the input signal, and wherein the digital signal is not changed when the output signal is larger than or equal to the input signal; and a digital-to-analog converter (DAC) configured to convert the digital signal to the output signal; wherein the control circuit comprises: a first comparator having a first input terminal, a second input terminal and an output terminal, wherein the first input terminal is configured to receive the input signal, the second input terminal is configured to receive the output signal, and wherein based on the input signal and the output signal, the first comparator generates a toggle control signal at the output terminal; and a logic circuit coupled to the first comparator to receive the toggle control signal, wherein based on the toggle control signal, the logic circuit generates the digital signal, and wherein the toggle operation of the digital signal is controlled by the toggle control signal.