A linear tunable amplifier for implantable neural recording applications

A fully integrated tunable low-noise amplifier for neural recording applications is presented that is highly linear over the entire signal band. A modified system design is presented to optimize the area/noise/linearity performance. A novel pseudo-resistor with improved linearity is also proposed. This design, simulated in a 0.18-μm CMOS process, consumes 41.4 μW from a 1.8-V supply. The simulated integrated input-referred noise is 2.61 μV_rms over 300 Hz to 10 kHz. The amplifier also provides an output swing of 1 V_P-P with a total harmonic distortion of -43.61 dB at 300 Hz and -46.41 dB at 10 kHz.