A Dual Mode Adjustable High Gain Ultra Low Noise Transimpedance Amplifier for Fine Dust Detection
This paper presents a dual mode adjustable high gain transimpedance amplifier (TIA) The TIA is designed with a high sensitivity to current bio signals for a fine dust detection system Integrated Circuit (IC) based on the operation of a photodiode module with high gain amplifications. Gain adjustment is implemented by coarse gain steps using selective loads with four different gain values and fine gain steps by 42 dBO during 16 fine steps. To improve the settling time, a capacitive compensation is applied for the last stage. An off state circuitry is proposed to avoid any off current leakage. This TIA is designed in a 0.18 mm standard CMOS technology, output reached high gains from 149 dBO up to 216 dBO with 67 dBO gain variation range, input referred noise less than 600 fA/ Hz in low frequencies and less then 27 fA/ Hz at 20 KHz, a minimum detectable current signal of 4 pA, and has a power consumption of 2.71 mW.
2020 IEEE International Symposium on Circuits and Systems (ISCAS)