CAJ | 학술논문

HgCdTe e-APD工作于线性模式，通过内雪崩倍增效应将一个微弱的信号放大多个数量级。介绍了一个具有列共用ADC制冷型(77 K)数字化混成式HgCdTe e-APD FPA读出电路，可以应用于门控3D-LARDAR成像，有主被动双模式成像功能。 Sigma-delta转换器比较适合于中规模128×128焦平面列共用ADC。调制器采用2-1 MASH单比特结构，开关电容电路实现，数字抽取滤波器采用CIC级联梳状滤波器。采用GLOBALFOUNDRIES 0.35μm CMOS工艺，中心距100μm。设计了量化噪声抵消逻辑消除第一级调制器量化噪声，采用数字电路实现。CIC抽取滤波器的每一级寄存器长度以方差为指标截尾，以降低硬件消耗。并且数字抽取滤波器工作电压降低到1.5 V，可以进一步降低功耗。仿真显示sigma-delta转换器精度大于13 bit，功耗小于2.4 mW，转换速率7.7 k Samples/s。
HgCdTe e-APD공작우선성모식，통과내설붕배증효응장일개미약적신호방대다개수량급。개소료일개구유렬공용ADC제랭형(77 K)수자화혼성식HgCdTe e-APD FPA독출전로，가이응용우문공3D-LARDAR성상，유주피동쌍모식성상공능。 Sigma-delta전환기비교괄합우중규모128×128초평면렬공용ADC。조제기채용2-1 MASH단비특결구，개관전용전로실현，수자추취려파기채용CIC급련소상려파기。채용GLOBALFOUNDRIES 0.35μm CMOS공예，중심거100μm。설계료양화조성저소라집소제제일급조제기양화조성，채용수자전로실현。CIC추취려파기적매일급기존기장도이방차위지표절미，이강저경건소모。병차수자추취려파기공작전압강저도1.5 V，가이진일보강저공모。방진현시sigma-delta전환기정도대우13 bit，공모소우2.4 mW，전환속솔7.7 k Samples/s。
HgCdTe electron injection avalanche photodiodes(e-APDs) work in linear mode. A weak optical current signal is amplified orders of magnitude due to the internal avalanche mechanism. The design of digital ROIC with a column-shared ADC for cooled (77 K) hybrid e-APDs FPA was presented in this paper. Sigma-delta conversion was a promising solution for high-performance and medium size FPA as 128 ×128. A multistage noise shaping (MASH) 2-1 single bit architecture sigma-delta ADC with switched-capacitor circuits was designed for column-shared ADC. A cascaded integrator-comb (CIC) filter was designed as the digital decimator filter. The circuit was implemented in the GLOBALFOUNDRIES 0.35μm CMOS process on the basis of a 100μm pixel pitch. A quantization noise subtraction circuit in modulator was designed to subtract the quantization noise of first-stage modulator. The register word length of the filter in each stage was carefully dimensioned in order to minimize the required hardware. Furthermore, the digital filters operate with a reduced supply voltage to 1.5 V. Simulation results showed that the sigma-delta conversion achieved the resolution higher than 13 bits and 2.4 mW power consumption per ADC at 7.7 k Samples/s rate.