Circuit and method for operating an analog-to-digital converter in multiple modes using ring oscillators

An analog digital converter comprising:

• an input to receive an analog signal;
• one or more ring oscillators comprising a plurality of rings and configurable to operate at least based on a programmable number of coupled rings of the plurality of rings;
• and
• circuitry coupled to the one or more ring oscillators, wherein the circuitry is programmable to:
• receive a selection of a number of coupled rings and a number of phases;
• configure the one or more ring oscillators to operate at least based on the number of coupled rings;
• cause the configured one or more ring oscillators to receive the analog signal and output a plurality of signals having respective phases corresponding to the number of phases;
• and
• convert the plurality of signals to one or more digital signals.

A device comprising:

• one or more ring oscillators configured to receive an input signal and output a plurality of signals;
• and
• circuitry configured to convert the plurality of signals from the one or more ring oscillators to one or more digital signals, wherein
• the one or more ring oscillators comprises a multi-ring oscillator having first-to-Nth rings, each ring comprising first-to-Mth differential amplifiers, wherein N and M are integers greater than 1 and each differential amplifier has a first input and a first output that have a first polarity, and a second input and a second output that have a second polarity, and
• the first to Nth rings are cyclically coupled such that the second output of the Mth differential amplifier of the Nth ring is coupled to the first output of the first differential amplifier of the first ring.