Figure 2.
(A) Schematic of a standard capacitive-feedback amplifier for neural signal amplification of each channel. The mid-band gain Am is set by C1/C2, and gm is the transconductance of the operational transconductance amplifier (OTA). MOS-bipolar transistors act as pseudoresistors and are represented by simple resistors Rf. Gate voltage of the pseudoregister, stray capacitance, and reference voltage are respectively represented by Vg, Cg, and Vref. (B) Schematic of the low-noise amplifier with variable corner frequencies of low-and high-pass filters (see text for more detail).