Patent ID: 7148834

Claim:
An analog-to-digital converter comprising: a first converter stage, comprising: a first signal output to output a first output signal; a first comparison circuit configured to calculate a first control signal based on a comparison of a signal amplitude of a first input signal with amplitudes of at least two first reference signals; and a first generator circuit configured to output a second output signal derived from a level of the first input signal; a second converter stage, comprising: a second signal output to output a third output signal; a second comparison circuit configured to calculate a second control signal based on a comparison of a signal amplitude of the first output signal with an amplitude of at least two second reference signals; wherein the amplitudes of the at least two second reference signals of the second comparison circuit are determined by the first control signal; and a second generator circuit configured to output a fourth output signal derived from a level of the first output signal and from the first control signal; and an amplification unit, comprising an input coupled to the first converter stage in a first switching state via a first switching device to receive the second output signal or to couple to the second converter stage in a second switching state via the first switching device to receive the fourth output signal.