Calibration of high speed ananlog-to-digital converters

A method comprising:

• providing, from a signal generator, a first signal during a calibration mode;
• providing, using parallel analog-to-digital converters (ADCs), ADC outputs associated with the first signal;
• providing, using first parallel filters, derivative signals associated with the ADC outputs;
• providing, using second parallel filters, first band-stop filtered signals associated with the ADC outputs;
• providing, using third parallel filters, second band-stop filtered signals associated with the derivative signals;
• multiplying, using a first multiplier circuit, the first and the second band-stop filtered signals to provide first multiplied signals including correlation information from the first and the second band-stop filtered signals;
• selecting, using an adaptive gain circuit, a portion of the first multiplied signals;
• and
• providing, from an accumulator circuit, accumulator output for the selection of the portion of the first multiplied signals, wherein the accumulator output is stored into a memory circuit.