Methods and apparatus to capture switch charge injections and comparator kickback effects

An apparatus comprising:

• first analog to digital converter (ADC) circuitry, the first ADC circuitry to include:
• capacitive digital to analog converter (C-DAC) circuitry including a switches, respective ones of the switches configured to transition between an open state and a closed state based on a switch signals;
• and
• controller circuitry configured to provide the switch signals to cause the C-DAC circuitry to:
• configure the switches into a first configuration to sample a differential analog input signal, wherein configuring switches into a first configuration includes:
• (a) a transition of a first switch and a second switch to the closed state, and (b) a transition of a third switch to the open state;
• configure the switches into a second configuration to convert the sample into a digital value, wherein configuring switches into a second configuration includes:
• (a) a transition of the first switch and the second switch to the open state, and (b) a transition of the third switch to the closed state;
• configure the switches into a third configuration to discharge a capacitor in the C-DAC circuitry, wherein configuring switches into the third configuration includes a transition of the first switch and the second switch to the closed state, wherein configuring switches into the third configuration begins an Auto Zero (AZ) phase with the third switch in the closed state;
• configure the switches into a fourth configuration to repeat the transition of the third switch to the open state corresponding to the first configuration;
• configure the switches into a fifth configuration to repeat the transition of the first switch and the second switch to the open state corresponding to the second configuration;
• configure the switches into a sixth configuration to repeat the transition of the third switch to the closed state corresponding to the second configuration;
• and
• perform an AZ decision with the switches in the sixth configuration;
• digital to analog converter (DAC) circuitry configured to convert the first set of digital bits to an analog voltage;
• and
• second ADC circuitry configured to:
• receive a difference between the differential analog input signal and the analog voltage;
• and
• convert the difference into a second set of digital bits, the second set corresponding to the least significant bits of a digital value.

A method comprising:

• providing, with controller circuitry, switch signals to capacitive digital to analog converter (C-DAC) circuitry, the C-DAC circuitry including switches, respective ones of the switches configured to transition between an open state and a closed state based on a plurality of switch signals;
• configuring, with the switch signals, the switches into a first configuration to sample a differential analog input signal, wherein configuring switches into a first configuration includes:
• (a) a transition of a first switch and a second switch to the closed state, and (b) a transition of a third switch to the open state;
• configuring, with the switch signals, the switches into a second configuration to convert the sample into a digital value, wherein configuring switches into a second configuration includes:
• (a) a transition of the first switch and the second switch to the open state, and (b) a transition of the third switch to the closed state;
• configuring, with the switch signals, the switches into a third configuration to discharge a capacitor in the C-DAC circuitry, wherein configuring switches into the third configuration includes a transition of the first switch and the second switch to the closed state, wherein configuring switches into the third configuration begins an Auto Zero (AZ) phase with the third switch in the closed state;
• configuring, with the switch signals, the switches into a fourth configuration to repeat the transition of the third switch to the open state corresponding to the first configuration;
• configuring, with the switch signals, the switches into a fifth configuration to repeat the transition of the first switch and the second switch to the open state corresponding to the second configuration;
• configuring, with the switch signals, the switches into a sixth configuration to repeat the transition of the third switch to the closed state corresponding to the second configuration;
• and
• performing an AZ decision with the switches in the sixth configuration.