Original scientific paper

https://doi.org/10.17559/TV-20250107002243

A High-Performance Fully Differential Low Noise Trans-Impedance Amplifier for Near Infra-Red Spectroscopic Systems

Muthukumaran B. ; Department of Electronics and Communication Engineering, SRM Institute of Science and Technology, College of Engineering and Technology, Kattankulathur, 603203, Tamilnadu, India *
Ramachandran B. ; Department of Electronics and Communication Engineering, SRM Institute of Science and Technology, College of Engineering and Technology, Kattankulathur, 603203, Tamilnadu, India

* Corresponding author.

Abstract

A Fully Differential Low Noise Trans-Impedance Amplifier (FDLN-TIA) with a high Common-Mode Rejection Ratio (CMRR) and Power-Supply Rejection Ratio (PSRR) is proposed for Near Infra-Red Spectroscopic (NIRS) systems. These systems require highly sensitive and precise circuits to detect ultra-low input currents effectively. The presented TIA is designed using a two-stage architecture to achieve a maximum Trans-Impedance Gain (TIG) of 193.24 dBΩ, ensuring accurate signal amplification. The amplifier demonstrates an impressive -3 dB bandwidth of 38.71 MHz, making it suitable for high-frequency applications. The proposed TIA efficiently senses and amplifies ultra-low input currents ranging from 100 pA to 200 pA. A novel modified fully differential amplifier architecture is introduced to achieve low noise performance, enabling effective noise cancellation. A Common Mode Feedback (CMFB) circuit and a power supply noise filter are integrated to improve the CMRR and PSRR, measured at 88.27 dB and 76.35 dB, respectively. The amplifier exhibits an input referred noise current of 0.95 fA/√Hz and an output noise voltage of 1.72 pV/√Hz, contributing to a Signal-to-Noise Ratio (SNR) of 237 dB at 38.71 MHz. The Figure of Merit (FoM) is calculated to be 4.76 × 10³⁵, highlighting the amplifier's efficiency. Operating from a 1 V supply voltage, the TIA consumes only 8.31 µW power at 27 °C, demonstrating its low-power characteristics. Post-layout simulations confirm the amplifier's performance, and the compact layout, measuring 61.29 µm × 60.61 µm in 45 nm CMOS technology, makes it suitable for integration into modern NIRS systems. This design is a promising solution for enhancing the sensitivity and reliability of NIRS applications with the best noise cancellation.

Keywords

CMOS technology; fully differential amplifier; noise cancellation; Near Infra-Red Spectroscopy (NIRS); trans-impedance gain

Hrčak ID:

335089

URI

https://hrcak.srce.hr/335089

Publication date:

30.8.2025.

Visits: 449 *