Analog-to-digital converter, ADC, a method for controlling said ADC, and a method for controlling a digital-analog-converter for said ADC

An analog-to-digital converter, ADC, comprising:

• a comparator having a first input and a second input;
• a first digital-to-analog converter, DAC, comprising a first capacitor bank having N number of first capacitors, wherein first plates of the first capacitors of the N number of first capacitors are controlled by bits of a first digital reference signal and wherein second plates of the first capacitors of the N number of first capacitors are configured to receive a sampled first input signal of a differential input signal, wherein the first digital reference signal represents a signed binary value, and wherein the first DAC is configured to supply a first input voltage to the first input of the comparator,
• wherein the first digital reference signal has N+1 number of bits, wherein a most significant bit of the N+1 number of bits is a sign bit, and remaining N bits of the N+1 number of bits are configured to respectively control the N number of first capacitors;
• and
• a second DAC, comprising a second capacitor bank having N number of second capacitors, wherein first plates of the second capacitors of the N number of first capacitors are controlled by bits of a second digital reference signal and wherein second plates of the second capacitors of the N number of second capacitors are configured to receive a sampled second input signal of the differential input signal, wherein the second digital reference signal represents a signed binary value, and wherein the second DAC is configured to supply a second input voltage to the second input of the comparator,
• wherein the second digital reference signal has N+1 number of bits, wherein a most significant bit of the N+1 number of bits is a sign bit, and remaining N bits of the N+1 number of bits are configured to respectively control the N number of second capacitors,
• wherein the ADC is configured to compare the first and second input voltages and, based on said comparison, adjust the first digital reference signal or the second digital reference signal so as to approximate a difference between the first and second input signals, and
• wherein the ADC is configured to selectively change the first digital reference signal or the second digital reference signal in dependence of said comparison.