A High-Gain Transimpedance Amplifier Using Highly-Linear and Symmetric Multi-Stage Pseudo-Resistors

This paper presents a high gain, low power, and highly linear structure for integrator-differentiator transimpedance amplifiers (TIAs) employed in biological recording systems. In order to improve the linearity of the structure, a symmetric and highly-linear pseudo resistor is proposed with a required current reference circuit. Based on the post-layout simulation results in a 180-nm CMOS technology, the proposed structure presents a flat AC response in a frequency range of 2.5Hz–100kHz, a tunable transimpedance gain of 430MΩ-1.7GΩ, an input-referred current noise of $2{\text{fA}}/\sqrt {{\text{Hz}}} $ at 10kHz, and a THD of 2%.