High resolution, high dynamic range analog-to-digital converter system and related techniques

An analog-to-digital converter system for sampling an input signal, comprising:

• a plurality of offset channels, each channel comprising:
• a differential amplifier having a signal input coupled to the input signal, an offset input for receiving an offset signal and an amplified difference output;
• and
• an analog-to-digital converter having a signal input coupled to the amplified difference output and having a signal output;
• and
• an offset controller having a plurality of outputs coupled to corresponding ones of the plurality of offset channels and a plurality of inputs coupled to corresponding ones of the plurality of the plurality of analog-to-digital converter signal outputs.

A method for digitizing an analog input signal comprising:

• providing at least one offset channel coupled to the analog signal;
• providing an offset index to each of the at least one offset channels for providing an offset signal;
• calculating a threshold for at least one offset channel;
• subtracting the offset signal from the analog signal to provide a difference signal;
• amplifying the difference signal;
• digitizing the amplified difference signal at each of the at least one offset channels;
• storing a at least one offset channel digitized amplified difference signal;
• and
• calculating a difference between the digitized amplified difference signal and a stored offset channel digitized amplified difference signal.

A method for converting an analog input signal comprising:

• providing a plurality of offset channels coupled to the analog input signal;
• selecting one of the plurality of offset channels as a working offset channel;
• providing a different offset index to each of the plurality of offset channels to provide a corresponding plurality of offset signals;
• subtracting the plurality of offset signals from the analog input signal to provide a corresponding plurality of difference signals;
• amplifying the plurality of difference signals;
• digitizing each of the plurality of amplified difference signals;
• calculating a threshold for the working offset channel;
• sensing whether the working offset channel amplified difference signal has exceeded the threshold of the working offset channel;
• storing a working offset channel digitized amplified difference signal;
• calculating a difference between the working offset channel digitized amplified difference signal and the stored working offset channel digitized amplified difference signal;
• and
• adjusting selected ones of the offset indices in response to sensing that the working offset channel digitized amplified difference signal has exceeded the threshold.