An active CMOS optical receiver employing an inductor-less, low-noise and high-gain regulated cascode transimpedance amplifier

摘要

This paper deals with a high-gain, active, modified RGC transimpedance amplifier with low noise characteristic operating in a 2.5 Gb/s optical receiver. By adding an extra transistor to the booster amplifier of an RGC circuit, and manipulating the trade-off between the frequency bandwidth and transimpedance gain, the transimpedance gain of 60 dB? is obtained, which reduces the input referred noise and enlarges the SNR of the circuit, while, consumes 760 ?W power using 65 nm CMOS process. The TIA stage, also, occupies a small area due to existence of only five transistors in its structure. The circuit is mathematically analyzed and related simulations justify its proper performance as not only a 2.5Gbps TIA, but also as a 5Gbps TIA. Finally, the presented TIA is followed by three stages of an NMOS-PMOS differential limiting amplifier to test its behavior as a complete 2.5 Gb/s optical receiver, which provides 850704? gain with dissipating power of 5 mW.