Two-stage reading circuit based on relaxation ferroelectric monocrystalline pyroelectric detector

Abstract

The invention discloses a two-stage reading circuit based on a relaxation ferroelectric monocrystalline pyroelectric detector, and the reading circuit comprises a first-stage CTIA (capacitor feedback mutual conductance) input stage circuit, a switching capacitor low-pass filter, a second CTIA amplification circuit, and a sampling output circuit. The first-stage CTIA input stage circuit enables an output current signal of the relaxation ferroelectric detector to be converted into a voltage signal, and the switching capacitor low-pass filter inhibits external noises. The second CTIA amplification circuit enables the signal to be amplified, and the sampling output circuit carries out signal sampling. All channels are conducted for sequential output. A circuit module is integrated on an integrated circuit chip, and is connected with a detector chip. An external drive circuit is used for providing a control signal, and the bandwidth of the low-pass filter is controlled through the adjustment of external clock frequency. The second CTIA amplification circuit achieves the further amplification of the signal, and improves the signal to noise ratio of the signal, thereby providing a large-scale multi-element small-area sensitive pyroelectric focal plane. The circuit provided by the invention is linear in output, is high in signal to noise ratio, and is an integrated weak signal reading circuit.

Description

technical field [0001] The invention relates to a detector readout circuit, in particular to a dual-stage readout circuit of a relaxation ferroelectric single crystal pyroelectric detector. Background technique [0002] Relaxor ferroelectric single crystal material is a new type of pyroelectric material with excellent pyroelectric comprehensive performance. It has very high pyroelectric coefficient, relatively low thermal diffusivity, relatively stable chemical properties, and is easy to improve the lateral Resolution, easy processing and thinning, can reduce the thickness of the crystal element, can improve detection ability and resolution. However, since the detection signal of ferroelectric material infrared devices depends on the area of ​​the sensitive element, as the resolution of the focal plane detector increases, the surface elements become smaller and smaller, and the pyroelectric current becomes weaker and weaker, which limits the detection technology. The key to...

AI Technical Summary

Problems solved by technology

The single-stage CTIA (capacitance feedback mutual conductance) structure realizes the amplification of small signals within a limited integration time, mainly by reducing the integration capacitance, but too small integration capacitance brings large KTC noise, which makes the signal submerged by noise. Difficult to do signal processing

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