Comparator circuit having a calibration circuit

摘要

A comparator has a first terminal, a second terminal, and an output terminal. A selection circuit is coupled to the first terminal. A calibration circuit is coupled to the output terminal and the second terminal. The comparator is configured to operate in a first mode when the selection circuit provides a first input signal to the first terminal and the calibration circuit provides a second input signal to the second terminal. The comparator is configured to operate in a second mode when the selection circuit provides a first calibration signal to the first terminal and the calibration circuit provides a second calibration signal to the second terminal based on an output signal at the output terminal. The comparator generates the output signal based on the first calibration signal and the second calibration signal.

主权项

1. A comparator circuit comprising:
a comparator having a first terminal, a second terminal, and an output terminal; a selection circuit coupled to the first terminal; and a calibration circuit coupled to the output terminal and the second terminal, wherein
the comparator is configured to operate in a first mode when
the selection circuit is configured to provide a first input signal to the first terminal of the comparator;the calibration circuit is configured to provide a second input signal to the second terminal of the comparator;the comparator is configured to operate in a second mode when
the selection circuit is configured to provide a first calibration signal to the first terminal of the comparator and the calibration circuit is configured to provide a second calibration signal to the second terminal of the comparator based on an output signal at the output terminal of the comparator; andthe comparator is configured to generate the output signal based on the first calibration signal and the second calibration signal;the calibration circuit includes
a first node coupled to a first capacitive circuit; anda second node coupled to a second capacitive circuit;in a first phase of operation, the calibration circuit is configured to selectively receive at the first node a first reference voltage or a second reference voltage based on the output signal at the output terminal of the comparator, the first and second reference voltages having different voltage levels; andin a second phase of operation, the calibration circuit is configured to transfer a voltage at the first node to the second node.