Work

Bandwidth Extension of Resistive-Feedback CMOS Inverter Amplifier Using T-Coil Peaking

Year: 2025

Type: article

Abstract: This paper presents a broadband CMOS three-stage resistive-feedback inverter (RFI) amplifier for high-speed applications. A novel T-coil-based peaking technique is proposed, combining over-shunt and gate peaking to extend the bandwidth with reduced inductance. Theoretical analysis derives design equations and shows that the proposed structure achieves a bandwidth extension ratio of 2.3, matching conventional gate peaking performance with only one-third the inductance, thereby enabling chip area reduction. Fabricated in a 28 nm fully depleted silicon-on-insulator CMOS process, the amplifier occupies an active area of only 0.0094 mm2. Small-signal measurements show a gain of 16.2 dB, a 3-dB bandwidth of 31.5 GHz (gain-bandwidth product (GBW) =203.38 GHz), and low power consumption of 5.6 mW. The measured eye diagram confirms reliable performance, with an output amplitude of 333.4 mVpp, signal-to-noise ratio of 8.9, rise time of 15.0 ps, and fall time of 15.3 ps, meeting the 28 Gbps non-return-to-zero signaling requirements. Compared to previous broadband CMOS amplifiers, the proposed T-coil peaking RFI amplifier demonstrates superior GBW performance in terms of active area and power consumption.

Source: IEEE Access

DOI: 10.1109/access.2025.3592770

Authors: Minkyung Choi, Hyungeun Kim, Jaehyun Park, Jongshin Shin, Jinho Jeong

Institutions: Sogang University, Samsung (South Korea), Samsung Electronics (South Korea)

Language: English

Topic: Radio Frequency Integrated Circuit Design

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,075

Funder: Samsung