Predictive sigma-delta ADC filter for power consumption

A method of calculating an output in a sigma-delta analog-to-digital converter, comprising:

• receiving, at an ADC filter of the sigma-delta analog-to-digital converter, a segment of L binary samples from a sigma-delta modulator of the sigma-delta analog-to-digital converter;
• predicting, at a predictor circuit of the ADC filter, whether a power consumption of a first summing method would be higher than a power consumption of a second summing method, based on a content of the segment;
• calculating the output using the first summing method in an accumulator circuit of the ADC filter, in a case where the power consumption of the first summing method would be lower than a power consumption of the second summing method;
• and
• calculating the output using the second summing method in an accumulator circuit of the ADC filter, in a case where the power consumption of the first summing method would be higher than a power consumption of the second summing method.

An image sensor, comprising:

• a pixel array;
• and
• a sigma-delta analog-to-digital converter, including a sigma-delta modulator and an ADC filter configured to receive a segment of L binary samples from the sigma-delta modulator, L being a positive integer, the ADC filter having:
• a predictor circuit configured to determine whether a power consumption of a first summing method would be higher than a power consumption of a second summing method, based on a content of the segment, and
• an accumulator circuit configured to calculate an output using the first summing method in a case where the power consumption of the first summing method would be lower than the power consumption of the second summing method, and using the second summing method in a case where the power consumption of the first summing method would be higher than the power consumption of the second summing method.