Integrating pre-circuit of reading circuit in infrared focal plane array detector

Abstract

An embodiment of the invention discloses an integrating pre-circuit of a reading circuit in an infrared focal plane array detector. The integrating pre-circuit comprises a first operational amplifier, a second operational amplifier, a bridge branch and an output offset branch. The output offset branch comprises a digital-to-analog converter, a first transistor, a second transistor and an adjustable resistor. An output end of the digital-to-analog converter is connected to a gate of the first transistor. A drain of the first transistor is connected to a source of the second transistor. A source of the first transistor is connected to a system power supply. A drain of the second transistor is grounded through the adjustable resistor. A gate of the second transistor is connected to offset voltage. The drain of the first transistor is further connected to a same-phase input end of the first operational amplifier through a second resistor. The voltage input to the same-phase input end of the first operational amplifier can be adjusted to the expected value by adjusting a digital-to-analog conversion circuit and the adjustable resistor, so that maladjustment of the whole integrating pre-circuit is eliminated and the integrating pre-circuit is allowed to output the ideal value.

Description

technical field [0001] The invention relates to a readout circuit of an infrared focal plane array detector, in particular to an integral front-end circuit of the readout circuit of an infrared focal plane array detector. Background technique [0002] All objects emit thermal radiation related to their temperature and material properties. The thermal radiation of objects near the ambient temperature is mostly in the infrared band, with a wavelength of about 1 μm (micrometer) to 24 μm. Infrared radiation provides a wealth of information in the objective world. It is the goal that people pursue to convert invisible infrared radiation into measurable signals and make full use of this information. The infrared focal plane array is an important optoelectronic device to obtain the infrared radiation information of the scene. [0003] The most widely used infrared focal plane array is the microbolometer detector, which is a thermistor resistive detector. The microbolometer focal ...

AI Technical Summary

Problems solved by technology

However, nominally identical devices have a finite amount of mismatch (i.e., mismatch) due to the uncertainty of each step in the manufacturing process

The incomplete matching of the two input MOS transistors of the operational amplifier leads to the generation of offset voltage, which causes output offset and greatly affects the output result.

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