Multi-bit successive approximation ADC

摘要

Examples are provided for converting an analog signal to a digital signal by processing more than one bit per cycle in a number of successive approximation cycles. A system may include capacitive sub-DAC circuits and comparators. Switches may isolate the capacitive sub-DAC circuits during one or more first cycles, and merge the sub-DAC circuits during one or more last cycles. A successive approximation register (SAR) may generate digital output signals or DAC digital signals. In another example, a system may include a DAC circuit. An input capacitor may be pre-charged to at least one of an analog input signal and a DAC analog signal. A programmable gain amplifier may amplify an error signal. A multi-bit ADC may convert the amplified error signal to a multi-bit digital signal. An SAR may use the multi-bit digital signal to generate a DAC digital signal or a digital output signal.