Design and Verification of Ultra Low Current Mode Amplifier Aiming at Biosensor Applications
Along with the booming of research and production of CMOS integrated bio-sensing system (IBS), ultra low current mode amplifier which serves for biosensor signal pre-amplification implemented in modern CMOS technology is in high demand in areas like ultra low bio-current analysis and detection, DNA probing and surveying systems and etc. In this paper, a novel current mode pre-amplifier (CMPA) module has been presented and verified in SMIC 0.18 mum CMOS process by elaborately considering gain, bandwidth, noise, and mismatch. The proposed CMPA solved the noise, bandwidth, and current headroom dilemma in the reported works, and can completely satisfy the specifications of IBS and stably provide a current gain of 20 dB, 3 dB band width of 7.03 kHz and input dynamic range of 20 bit, with only InA of DC quiescent current, while the input offset current and noise current are less than 16.0 pA and 4.67pArms, respectively.