Time domain interpolation scheme for flash A/D converters

A method of analog-to-digital conversion comprising:

• comparing a first reference voltage with a signal voltage;
• outputting a first negative output and a first positive output based on comparing the first reference voltage with the signal voltage;
• comparing a second reference voltage with the signal voltage, the second reference voltage being different than the first reference voltage;
• outputting a second negative output and a second positive output based on comparing the second reference voltage with the signal voltage;
• comparing the first positive output with the second negative output;
• and
• outputting a first arrival time comparator output based on comparing the first positive output with the second negative output.

An analog-to-digital converter circuit comprising:

• a first voltage comparator coupled to a first reference voltage and a signal voltage, the first voltage comparator having a first positive output for outputting a comparison of the first reference voltage with the signal voltage;
• a second voltage comparator coupled to a second reference voltage and the signal voltage, the second reference voltage being different than the first reference voltage, the second voltage comparator having a second negative output for outputting a comparison of the second reference voltage with the signal voltage;
• and
• a first arrival time comparator coupled to the first positive output and the second negative output, the first arrival time comparator having a first arrival time comparator output for outputting a comparison of the first positive output with the second negative output.