System and method for analog-to-digital converter (adc) with repressed input current

A method, comprising:

• receiving, by an amplifier, a first signal;
• receiving, by a first switch coupled between the amplifier a capacitor, a second signal from the amplifier;
• with a third switch being on, turning on the first switch and a second switch to initiate charging of the capacitor, wherein the second switch is coupled between the capacitor and the ADC, the third switch is coupled between the amplifier and the first switch;
• in response to turning off the third switch, turning off the second switch to complete charging of the capacitor;
• and
• responsive to completing charging of the capacitor, turning off the first switch to control the ADC to convert the second signal to a digital signal.

Circuitry comprising:

• a controller configured to control a first switch, a second switch, and a third switch, wherein
• the first switch is coupled between an amplifier and a capacitor, the amplifier configured to receive a first signal and output a second signal, the capacitor coupled between the amplifier and an analog-to-digital converter (ADC),
• the second switch is coupled between the capacitor and the ADC,
• the third switch is coupled between the amplifier and the first switch, and
• the controller is configured to:
• with the third switch being closed, close the first switch and the second switch to initiate charging of the capacitor;
• in response to opening the third switch, opening the second switch to complete charging of the capacitor;
• and
• responsive to completing charging of the capacitor, open the first switch to control the ADC to convert the second signal to a digital signal.