Analog-to-digital converters

An analog-to-digital converter (ADC) comprising:

• a first successive approximation register (SAR) analog-to-digital architecture comprising:
• at least one digital-to-analog converter (DAC) configured so as to receive an analog input signal and at least one digital code and generate an output signal therefrom;
• at least one comparator configured so as to receive the output signal from the at least one DAC at a first input, and provide a bit output based at least in part on a comparison between at least one reference signal and the output signal received from the at least one DAC;
• and
• a logic circuit configured so as to provide a first digital code to the at least one DAC and subsequent digital codes in response to the bit output from a preceding comparison step, control the operation of the at least one comparator, receive the bit output from the at least one comparator, and generate a first output code;
• wherein the at least one DAC comprises a first DAC and a second DAC, the first and second DACs arranged in parallel and configured so as to receive the analog input signal and digital code, the first and second DACs together with the at least one comparator forming respective first and second paths, the first path being configured for deriving odd bits in the digital code and the second path being configured for deriving even bits in the digital code;
• and wherein the first DAC is further configured so as to perform feedback steps for derived bits of the digital code while the at least one comparator performs comparison steps for even bits of the digital code, and the second DAC is further configured so as to perform feedback steps for derived bits of the digital code while the at least one comparator performs comparison steps for odd bits of the digital code,
• a third DAC configured so as to receive the input signal and the first output code from the first SAR analog-to-digital architecture and provide an output signal to an analog-to-digital converter (ADC) architecture configured so as to generate a second output code based at least in part on the output signal;
• and
• a combiner configured so as to receive the first and second output codes and generate an output signal based at least in part on the output codes.

A method of converting an analog signal to a digital signal, the method comprising:

• receiving an analog input signal using at least one digital-to-analog converter (DAC);
• providing a first digital code to the at least one DAC from a logic circuit;
• processing the analog input signal together with the first digital code in the at least one DAC;
• generating an output signal from the at least one DAC;
• receiving the output signal from the at least one DAC at a first input of at least one comparator;
• acquiring a comparison of the output signal and at least one reference signal;
• generating a bit output based at least in part on the comparison;
• receiving the bit output from the at least one comparator at the logic circuit and generating a subsequent digital code in accordance with the bit output;
• and
• controlling operation of the at least one comparator and the first and second DACs using the logic circuit;
• generating an output signal from the logic circuit after repeating at least a subset of the preceding steps using the bit output from the at least one comparator;
• and
• for each digital code:
• deriving odd bits of the digital code using a first DAC and the at least one comparator and even bits of the digital code using a second DAC and the at least one comparator;
• and
• performing feedback steps for the derived bits of the digital code while processing the even bits of the digital code, and performing feedback steps for the derived bits of the digital code while processing the odd bits of the digital code.