CMOS transimpedance amplifier for biosensor signal acquisition

Mark M. R. Ibrahim, Peter M. Levine
2014 2014 IEEE International Symposium on Circuits and Systems (ISCAS)  
A 1-GΩ CMOS transimpedance amplifier (TIA) suitable for processing sub-nA-level currents in electrochemical biosensor signal-acquisition circuits is presented. Use of a twostage active transconductor provides resistive feedback in place of a large-area linear resistor. The TIA feedback loop is engineered to suppress output offset caused by DC input leakage currents of ±0.9 nA. A mechanism to tune the low-frequency cutoff of the TIA from 0.7 Hz to 500 Hz is implemented which permits operation
more » ... er variable environmental conditions. Simulated and experimental results from a custom TIA fabricated in a 3.3-V 0.35-µm CMOS process are presented. v
doi:10.1109/iscas.2014.6865056 dblp:conf/iscas/IbrahimL14 fatcat:ixrcq4eyszgv3okk6joaqc7aze