A High-Precision Single-Ended-Current-to-Differential-Voltage Converter for Reconfigurable Neural Recording Front-Ends

This paper presents a high-precision single-ended-current-to-differential-voltage (SC-DV) converter that is used in the reconfigurable neural recording front-end. For processing neural signals detected by current-mode sensors in a differential way, a single-ended-current signal is converted into a differential-voltage signal with low power consumption and low-noise performances. The proposed SC-DV converter is constructed by employing complementary diode-connected loads, a folded stage, and a replica stage to reduce the common-to-differential conversion error (V
Error
). In this work, two types of SC-DV converters are proposed, and their performances are compared to the conventional SC-DV converter. Implemented in a 180-nm standard CMOS process, the proposed SC-DV converters consume tens-of-nW power per channel and provide a-few-pA
rms
noise performance. Also, V
Error
is reduced dramatically compared to the conventional SC-DV converter.