1.8 V, variable gain transimpedance amplifiers with constant damping factor for burst-mode optical receiver

This paper presents the design of high sensitivity and wide dynamic range transimpedance amplifiers for a burst mode optical receiver. To achieve low noise and wide bandwidth design goals, both Butterworth and Bessel type TIAs are investigated, characterized, and design techniques for noise optimization are proposed. The conversion gain of the TIA is tunable with constant damping factor for wide dynamic range applications. Implemented in a 0.18 μm CMOS technology, the TIAs provide 66 dBΩ in the high gain mode, 57 dBΩ in the low gain mode, and are capable of operating up to 4.5 Gbps. The measured sensitivity is up to -23.3 dBm with 17 dB dynamic range at BER less than 10^-12. Operating under a 1.8 V supply, the power dissipations for Butterworth and Bessel type TIAs are about 37.8 mW and 43.2 mW, respectively. Chip size is 510 μm×520 μm.