Semiconductor device and infrared image pickup device provided with same

摘要

Provided is an infrared image pickup device, including: a plurality of bolometer elements that receive light from a subject; and a plurality of readout circuits respectively connected to the plurality of bolometer elements, the plurality of bolometer elements and the plurality of readout circuits being connected to a first input voltage wiring and a second input voltage wiring. Each of the plurality of readout circuits includes: a bias circuit that applies a bias voltage to corresponding one of the plurality of bolometer elements; a bias-canceling circuit that removes an offset current of the corresponding one of the plurality of bolometer elements; an integration circuit connected to a connection point between the bias circuit and the bias-canceling circuit, that integrates a differential current between the bias circuit and the bias-canceling circuit; and a saturation-prevention circuit that prevents saturation of an output voltage of the integration circuit.

主权项

1. An infrared image pickup device, comprising:
a plurality of bolometer elements that receive light from a subject; and a plurality of readout circuits respectively connected to the plurality of bolometer elements, the plurality of bolometer elements and the plurality of readout circuits being connected to a first input voltage wiring, a second input voltage wiring, and a reset signal wiring, wherein each of the plurality of readout circuits comprises:
a bias circuit that applies a bias voltage to corresponding one of the plurality of bolometer elements;a bias-canceling circuit that removes an offset current of the corresponding one of the plurality of bolometer elements;an integration circuit connected to a connection point between the bias circuit and the bias-canceling circuit, that integrates a differential current between the bias circuit and the bias-canceling circuit; anda saturation-prevention circuit that prevents saturation of an output voltage of the integration circuit, wherein the saturation-prevention circuit has a function of comparing the output voltage of the integration circuit with a preset saturation prevention upper detection voltage, and separates the integration circuit from the connection point when the output voltage of the integration circuit is higher than the preset saturation prevention upper detection voltage, wherein the saturation-prevention circuit comprises:
a first comparator that compares the output voltage of the integration circuit with the preset saturation prevention upper detection voltage; anda switch inserted and connected between the connection point and the integration circuit so as to be changed between a first state and a second state by an output of the first comparator, and wherein the switch connects the connection point to the integration circuit when the switch is in the first state, and the switch separates the connection point from the integration circuit and connects the connection point to a reference voltage when the switch is in the second state.