摘要
CMOS电路是高输入阻抗,而长波红外光导探测器是低阻抗,实现低阻抗红外光导探测器与CMOS电路的良好匹配,是目前长波红外探测器高性能成像的关键技术。文中设计了一种能在低温下工作的低阻抗红外光导探测器CMOS电路,差分放大器采用正负电源供电,在输入级采用桥式输入方式,该电路第一级采用1 MΩ的负反馈电阻实现信号放大,第二级放大采用正端放大方式,输入级、第一级放大、第二级放大均采用直接耦合方式。测试结果表明,该放大器与长波红外低输入阻抗光导探测器连接后能正常工作,总放大倍数大于1万倍,3 dB带宽大于4 kHz,等效输入电压噪声小于1.5μV,有效地解决了低阻抗光导探测器与高阻CMOS电路的匹配问题。
To design low-temperature CMOS circuit for low impedance infrared photoconductive detector and realizing high performance IR imaging, the use of differential amplifier with symmetrical positive and negative power is necessary. Thus, a kind of two grade CMOS circuit was designed. The first grade was adopted bridge circuit input, this structure was fit for low impedance detector. The positive magnifying method was introduced in second grade. The feedback resistance was designed 1 MΩ, the circuit was supplied by ±1.5 V and this circuit was attached to detector without capacitance. The testing results show that the amplifier can work well when it connects with low-impedance infrared photoconductive detector at the low temperature . The circuit total gain exceeds 10 000 times , the 3 dB bandwidth is more than 4 kHz, and the equivalent input noise is less than 1.5μV. The research has perfectly solved the matching problem between high impedance CMOS circuit and low impedance detector.
出处
《红外与激光工程》
EI
CSCD
北大核心
2014年第3期762-765,共4页
Infrared and Laser Engineering
基金
上海市国际科技合作基金(09530708500)
关键词
低阻抗
低噪声
光导探测器
CMOS
low-impedance
CMOS
low-noise
photoconductive detector
