Large dynamic range digitizing apparatus and method

An apparatus and method for digitizing an analog signal and optimizing the dynamic range of the digitized signal. Dual analog-to-digital converters are preceded by respective amplifiers with different gains for receiving an analog input signal. The digital output signal from the analog-to digital converter preceded by the amplifier of higher gain is selected and stored when it is not clipped. Otherwise, the analog-to-digital converter preceded by the amplifier of lower gain is selected and its digital output signal is stored. Once digital memory is filled, an adaptive formatting program selects the most appropriate parts of the memory words to achieve maximum resolution and dynamic range in an output word size.