High Gain, Low Noise and Power Transimpedance Amplifier Based on Second Generation Voltage Conveyor in 65 nm CMOS Technology

A transimpedance amplifier (TIA) based on a voltage conveyor structure designed for high gain, low noise, low distortion, and low power consumption is presented in this work. Following a second-generation voltage conveyor topology, the current and voltage blocks are a regulated cascode amplifier and a down converter buffer, respectively. The proposed voltage buffer is designed for low distortion and low power consumption, whereas the regulated cascode is designed for low noise and high gain. The resulting TIA was fabricated in 65 nm CMOS technology for logic and mixed-mode designs, using low-threshold voltage transistors and a supply voltage of +/- 1.2 V. It exhibited a 52 dB omega transimpedance gain and a 1.1 GHz bandwidth, consuming 55.3 mW using a +/- 1.2 V supply. Our preamplifier stage, based on a regulated cascode, was designed considering detector capacitance, bonding wire, and packaging capacitance. The voltage buffer was designed for low-power consumption and low distortion. The measured input-referred noise of the TIA was 22 pA/root Hz. The obtained total harmonic distortion of the TIA was close to 5%. In addition, the group delay is constant for the considered bandwidth. Comparisons against published results in terms of area (A), power consumption (P), bandwidth (BW), transimpedance gain (G), and noise (N) are were performed. Both figures of merit FoMs-the ratio root (G x BW) and P x A-and FoM/N values demostrated the advantages of the proposed approach.

Automated summary

This work presents a transimpedance amplifier (TIA) based on a voltage conveyor structure, designed to achieve high gain, low noise, low distortion, and low power consumption. The voltage buffer is designed for low distortion and power consumption, while the regulated cascode is designed for low noise and high gain. The fabricated TIA exhibits excellent performance, including a high transimpedance gain and wide bandwidth, making it a promising solution for logic and mixed-mode designs.