Analog-to-digital conversion circuit, and image sensor including the same

摘要

One embodiment of an analog-to-digital converter includes at least one comparator and a restriction circuit. The comparator has first and second input nodes and a connection node. The connection node is one of an internal node and an output node of the comparator. The restriction circuit is electrically connected to the connection node, and the restriction circuit is configured to restrict a voltage of the connection node.

主权项

1. An image sensor, comprising:
a pixel array configured to generate at least one pixel signal; a ramp generator configured to generate a ramp signal; and an analog-to-digital converter configured to receive the ramp signal and the pixel signal, and generate a digital signal representing the pixel signal, the analog-to-digital converter including,
at least one comparator, the comparator having an output node configured to output a comparison result signal; anda restriction circuit electrically connected to the output node, the restriction circuit including a switch and a diode, the switch connected in series to the diode, the restriction circuit configured to suppress a change in total current by creating a current path between the output node and one of a ground and a power supply if the comparison result signal changes, the total current being a current flowing through the comparator plus a current flowing through the restriction circuit.