Analog to digital converter apparatus with time continuous input and corresponding method

An ultrasound detector for obstacle recognition based on time of flight evaluation, comprising:

• an analog-to-digital converter including:
• a flash analog-to-digital converter having an input and an output;
• an integrator having an input configured to receive an error signal and an output that is coupled to the input of the flash analog-to-digital converter;
• a feedback path including:
• a digital-to-analog converter configured to generate an output signal that is compared to an input signal of the analog-to-digital converter to obtain the error signal;
• and
• a controller coupled between the output of the flash analog-to-digital converter and the feedback path and configured to perform digital integration,
• wherein the flash analog-to-digital converter generates a digital output having quantized values that are represented by a number of bits, and the flash analog-to-digital converter includes a plurality of comparators having different thresholds, respectively, and the thresholds cover a range of a flash analog-to-digital converter input signal, and the range of the flash analog-to-digital converter input signal is less than two to a power of the number of bits minus one.

A method for performing analog-to-digital conversion, comprising:

• integrating, by an integrating stage, an error signal to generate a first signal;
• performing analog-to-digital conversion, by a flash analog-to-digital converter, on the first signal to generate an output signal;
• performing control including digitally integrating the output signal;
• feeding back the integrated output signal to a digital-to-analog converter;
• and
• comparing an output of the digital-to-analog converter to a continuous input signal to obtain the error signal,
• wherein the flash analog-to-digital converter provides the output signal as a digital output having a number of bits, the flash analog-to-digital converter includes a plurality of comparators having different thresholds, respectively, and the thresholds cover a range of the first signal, and the range is less than two to a power of the number of bits minus one.