Area-efficient and moderate conversion time analog to digital converter (ADC)

An analog-to-digital converter (ADC) for converting an analog input signal to a digital representation thereof, comprising:

• a sub-range selector that:
• determines a resolution of the input analog signal,
• determines an input analog signal range of the input analog signal based on the resolution;
• splits the input analog signal range into n+1 sub-ranges, n being a number of splits in the input analog signal range;
• assigns a respective N-bit coarse digital code i to each sub-range;
• identifies the input analog signal with a corresponding sub-range, the corresponding sub-range having a respective digital code i;
• and
• a delta-sigma circuit that:
• performs a delta-sigma operation on the input analog signal using upper and lower references of the corresponding sub-range that the input analog signal is identified with for a number of clocks L based on the resolution to produce the digital representation, by obtaining a fine digital code j and calculating a digital code k by adding the coarse digital code i to the fine digital code j.

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

• determining an input analog signal range of the input analog signal;
• splitting the input analog signal range into n+1 sub-ranges, n being a number of splits in the input analog signal range;
• assigning a respective N-bit coarse digital code i to each sub-range;
• identifying the input analog signal with a corresponding sub-range, the corresponding sub-range having respective digital code i;
• and
• performing a delta-sigma operation on the input analog signal using upper and lower references of the corresponding sub-range that the input analog signal is identified with, to produce the digital representation.