A Low-Power 45 nm CMOS Transimpedance Amplifier with Active Inductor Feedback for Fiber-Optic Applications

Abstract

Abstract: In this paper, a transimpedance amplifier (TIA) is introduced to obtain low power consumption with moderately high gain. The proposed TIA consists of two parts: in the first stage, a regulated cascade transimpedance amplifier (RGC TIA) input stage with active inductor local feedback is utilized for current gain enhancement, while a second stage is designed for TIA gain. The proposed TIA circuit is implemented in a 45 nm CMOS process technology. Simulation results show that the proposed TIA achieves a power consumption of 0.975 mW, while the TIA gain is increased up to 62.2 dBΩ at 1 GHz of  bandwidth. The conventional trade-off between gain and power consumption is relaxed, which represents the key finding of this work, while maintaining an input-referred noise current spectral density of 28pA/√Hz. The reported low power consumption was achieved at a 1V budget DC supply.

Keywords: Optical preamplifier, Fiber optics, RGC transimpedance, TIA gain.

PACs: 85.40.-e, 07.50. Ek, 84.30.-r