A 4 GHz Single-to-Differential Cross-Coupled Variable-Gain Transimpedance Amplifier for Optical Communication

Samuel B S Lee,Kiat Seng Yeo

doi:10.3390/electronics10233042

Samuel B S Lee, Kiat Seng Yeo

Open Access

https://doi.org/10.3390/electronics10233042

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Journal: Electronics	Publication Date: Dec 5, 2021
Citations: 2	License type: CC BY 4.0

Affiliation: Singapore University of Technology and Design

Abstract

This letter presents an inductorless transimpedance amplifier (TIA) for visible light communication, using the UMC 40 nm CMOS process. It consists of a single-to-differential input stage with a modified cross-coupled regulated cascode design, followed by a modified fT-doubler mid-stage with a combined active inductor and capacitive degeneration design for bandwidth-enhancement and differential output. The mid-stage also has an attached common-mode feedback (CMFB) circuit. Both the input and mid-stages have gain-varying and peaking-varying functions. It has a measured gain range of 37.5–58.7 dBΩ and 4.15 GHz bandwidth using a 0.5 pF capacitive load. The gain range results in an input dynamic range of 33.2 µA–1.46 mA. Its input referred noise current is 10.7 pA/Hz, core DC power consumption is 7.84 mW from a VDDTIA of 1.6 V and core area is 39 µm × 26 µm.

Highlights

Engineering Product Development, Singapore University of Technology and Design (SUTD), 8 Somapah Road, Abstract: This letter presents an inductorless transimpedance amplifier (TIA) for visible light communication, using the United Microelectronics Corporation (UMC) 40 nm CMOS process
This paper presents a nm two-stage single-to-differential cross-coupled enhancing methods such as capacitive degeneration and inductive peaking are commonly variable-gain TIA design with analysis of its key features, and it is taped-out and measured
This paper presents a 40 nm CMOS two-stage single-to-differential cross-coupled variable-gain TIA design with analysis of its key features, and it is taped-out and meas proposed TIA design is modified from the authors’ simulated fixed-gain design ured.The

Summary

Introduction

Engineering Product Development, Singapore University of Technology and Design (SUTD), 8 Somapah Road, Abstract: This letter presents an inductorless transimpedance amplifier (TIA) for visible light communication, using the UMC 40 nm CMOS process. It consists of a single-to-differential input stage with a modified cross-coupled regulated cascode design, followed by a modified f T -doubler mid-stage with a combined active inductor and capacitive degeneration design for bandwidth-enhancement and differential output. The mid-stage has an attached common-mode feedback (CMFB) circuit. Both the input and mid-stages have gain-varying and peaking-varying functions. The large, unused visible light spectrum (400–800 THz) is gaining increasing research attention for near-field visible light communication (VLC) [1]

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