Reading circuit of uncooled infrared focal plane array

Abstract

The embodiment of the invention discloses a reading circuit of an uncooled infrared focal plane array. The reading circuit of the uncooled infrared focal plane array comprises a current bias circuit, a substrate temperature compensating circuit and an integrating circuit, wherein the current bias circuit comprises a reference bias current source structure IBIAS, a channel-level thermal short circuit microbolometer RB and a pixel-level thermal insulation microbolometer RS, wherein the channel-level thermal short circuit microbolometer RB and the pixel-level thermal insulation microbolometer RS are same in current bias; the substrate temperature compensating circuit comprises a transconductance amplifier OTA; the input end of the transconductance amplifier OTA is connected onto the channel-level thermal short circuit microbolometer RB and the pixel-level thermal insulation microbolometer RS to generate voltage; the input end of the integrating circuit is connected to the output end of the transconductance amplifier OTA, and the integrating circuit is used for performing integration on the output current of the transconductance amplifier OTA to obtain output voltage VOUT. According to the reading circuit disclosed by the embodiment of the invention, the channel-level transconductance amplifier is additionally arranged in the reading circuit, so that the substrate temperature compensation is realized; a TEC (thermo-electric cooler) is removed, so that the size and the cost of packaging are greatly reduced, and meanwhile, the uniformity and the reliability of the whole circuit are greatly improved.

Description

technical field [0001] The invention relates to the technical field of an uncooled infrared focal plane array, in particular to a readout circuit of an uncooled infrared focal plane array. [0002] Background technique [0003] According to Planck's radiation theorem, any object with a temperature higher than absolute zero will have molecular thermal motion inside it, thereby producing infrared radiation with different wavelengths. Infrared radiation has important characteristics that its intensity and wavelength are directly related to the surface temperature of objects, providing rich information on the objective world, but it is an invisible electromagnetic wave, how to convert this infrared radiation into a measurable signal to detect the objective world Become the goal of human beings' constant struggle. [0004] The infrared focal plane array detector converts the temperature distribution of the target object into a video image by means of photoelectric conversion an...

AI Technical Summary

Problems solved by technology

However, after removing the TEC, the temperature of the pixel will rise after receiving infrared radiation, and the change of the substrate temperature will cause great non-uniformity of the focal plane array, which will affect the readout results.

Images