Valiable frequency characteristics multi-channel on-chip patch-clamp system using 0.18 um CMOS technology

Patch-clamp measurement system is one of the useful techniques in the field of Electrophysiology. This technique makes it possible to measure ion current and is expected to contribution of the treatment of neurological disease and elucidation of the neuronal activity. In this paper, we propose multi-channel patch-clamp measurement system. The system is composed of I-V converter, parasitic components compensation circuit, programmable gain amplifier, anti-aliasing filter, multiplexer, and serial to parallel converter. The current-to-voltage conversion rate of the whole system is a maximum 379 Gohm. The input referred current noise is achieved 1.86 pArms in simulation, 2.09 pArms in measurement. In order to fine tune the cutoff frequency of entire system, the variable capacitance is used for the filter. It is possible to eliminate the influence of variations between the channels in a multi-channel system. The system was fabricated using the 0.18um CMOS process. 8-channel system is implemented in a chip size of 2.5 mm times 5 mm.