Pre-amplification and measuring range automatic switching circuit for light intensity detection

Abstract

The invention discloses a pre-amplification and measuring range automatic switching circuit for light intensity detection. The circuit particularly comprises a photoelectric detector, a dark current compensating circuit, a pre-amplification circuit, a measuring range switching circuit and the like. According to the pre-amplification and measuring range automatic switching circuit, a PIN photodiode is adopted to convert light intensity signals into photocurrent signals, a precision chopped wave stable type operational amplifier is adopted to convert the photocurrent signals into voltage signals, the measuring range switching circuit is controlled by a single chip microcomputer and can be automatically switched among four measuring ranges, and influences generated by dark currents of the photodiode can be reduced through adjustment of the dark current compensating circuit. The pre-amplification and measuring range automatic switching circuit has the advantages of being low in noise, high in gain and common-mode rejection ratio, small in detuning, large in dynamic range of light intensity capable of being detected, and the like.

Description

technical field [0001] The invention relates to the field of light intensity detection. Background technique [0002] Since the dynamic range of the light intensity to be detected in the light intensity detection system may be very large, and the resolution and the measurement range must be considered during measurement, the use of automatic range conversion technology can better solve this problem. [0003] Most of the existing light intensity signal amplification circuits only pursue high gain, but ignore the consideration of the measurement range, and there are problems such as temperature drift, large noise, and large offset voltage, which cannot meet the actual application requirements of the light intensity detection system. Therefore, it is very necessary to develop a high-performance preamplifier and range automatic switching circuit for light intensity signal detection, which can take into account the resolution and measurement range. Contents of the invention ...

AI Technical Summary

Problems solved by technology

[0003] Most of the existing light intensity signal amplification circuits only pursue high gain, but ignore the consideration of the measurement range, and there are problems such as temperature drift, large noise, and large offset voltage, which cannot meet the actual application requirements of the light intensity detection system.

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