【摘要】 数字化读出电路是制冷型红外探测器的重要组成部分，它的本质是将模拟信号转换成数字信号，其中需要用到模数转换器(ADC)这个关键模块。常见的ADC中，Sigma-DeltaADC因其噪声整形和过采样技术简化了模拟电路结构，降低了动态功耗，成为低功耗ADC方面的首选。因此，对Sigma-Delta ADC的主要部分-调制器进行研究，十分具有意义。调制器电路采用二阶CIFF结构、77 K温度下进行设计，采用浮动反向放大器(Floating Inverter Amplifier)作为积分器的运放。完成了调制器的行为级建模与参数设计；基于SMIC 0.18μm CMOS工艺进行了电路级设计与仿真。仿真结果表明，在5 MHz采样频率、256的过采样率下，调制器的功耗为114.5μW,SNDR为90.28 dB,有效位数为14.7 bit。更多还原

【Abstract】 The digital readout circuit is a crucial component of refrigerated infrared detectors, as its primary function is to convert analog signals into digital signals.This process relies on the analog-to-digital converter(ADC) as a key module.Among common ADCs, the Sigma-Delta ADC stands out for its noise shaping and oversampling techniques, which simplify the analog circuit structure and reduce dynamic power consumption, making it the preferred choice for low-power ADCs.Therefore, studying the modulator—the main component of the Sigma-Delta ADC-is highly significant.The modulator circuit is designed using a second-order CIFF structure at 77 K temperature, with a floating inverter amplifier(FIA) serving as the operational amplifier for the integrator.Behavioral-level modeling and parameter design of the modulator are completed.Circuit-level design and simulation are conducted based on the SMIC 0.18 μm CMOS process.Simulation results show that at a sampling frequency of 5 MHz and an oversampling rate of 256,the modulator′s power consumption is 114.5 μW,the SNDR is 90.28 dB,and the effective number of bits is 14.7 bits.更多还原