Abstract: In accordance with an embodiment, a circuit includes a first oscillator having an oscillation frequency dependent on an input signal at a first input, where the first oscillator is configured to oscillate when an enable input is in a first state and freeze its phase or reduce its frequency when the enable input is in a second state. The circuit also includes a first time-to-digital converter having an input coupled to an output of the first oscillator, and a pulse generator having an input coupled to a first clock input of the circuit and an output coupled to the enable input of the first oscillator, where the pulse generator is configured to produce a pulse having pulse width less than a period of a clock signal at the first clock input.

Abstract: An analog-to-digital converter includes a ring oscillator having an input for receiving an analog signal, a coarse Gray code counter having a first input coupled to a first output of the ring oscillator and a second input for receiving a clock signal, a fine counter having first inputs coupled to secondary outputs of the ring oscillator and a second input for receiving the clock signal, a first difference generator having an input coupled to the output of the coarse counter, a second difference generator having an input coupled to the output of the fine counter, and an adder having a first input coupled to the output of the first difference generator, a second input coupled to the output of the second difference generator, and an output for providing a digital signal corresponding to the analog signal.

Abstract: In accordance with an embodiment, a circuit includes a first oscillator having an oscillation frequency dependent on an input signal at a first input, where the first oscillator is configured to oscillate when an enable input is in a first state and freeze its phase or reduce its frequency when the enable input is in a second state. The circuit also includes a first time-to-digital converter having an input coupled to an output of the first oscillator, and a pulse generator having an input coupled to a first clock input of the circuit and an output coupled to the enable input of the first oscillator, where the pulse generator is configured to produce a pulse having pulse width less than a period of a clock signal at the first clock input.

Abstract: In various embodiments, a circuit is provided. The circuit includes: a voltage biasing circuit coupled to a microelectro-mechanical system (MEMS) microphone sensor, the MEMS microphone sensor coupled to a driver circuit, and the driver circuit coupled to an oscillator-based ADC circuit. The oscillator-based ADC circuit may include an Nth order sigma-delta modulator, where N is an integer equal to or greater than 1.

Abstract: In various embodiments, a circuit is provided. The circuit includes: a voltage biasing circuit coupled to a microelectro-mechanical system (MEMS) microphone sensor, the MEMS microphone sensor coupled to a driver circuit, and the driver circuit coupled to an oscillator-based ADC circuit. The oscillator-based ADC circuit may include an Nth order sigma-delta modulator, where N is an integer equal to or greater than 1.