A 3.125-Gb/s inductorless transimpedance amplifier for optical communication in 0.35 μm CMOS

Abstract

A 3.125-Gb/s transimpedance amplifier (TIA) for an optical communication system is realized in 0.35 m CMOS technology. The proposed TIA employs a regulated cascode configuration as the input stage, and adopts DC-cancellation techniques to stabilize the DC operating point. In addition, noise optimization is processed. The on-wafer measurement results show the transimpedance gain of 54.2 dB and -3 dB bandwidth of 2.31 GHz. The measured average input referred noise current spectral density is about 18.8 pA/ p Hz. The measured eye diagram is clear and symmetrical for 2.5-Gb/s and 3.125-Gb/s PRBS. Under a single 3.3-V supply voltage, the TIA consumes only 58.08 mW, including 20 mW from the output buffer. The whole die area is 465 435 m 2 .

A wideband current-reuse-RGC TIA circuit with low-power consumption

“…Therefore, the bandwidth can be improved by lower the input impedance of TIAs [21]. Consequently, a regulatedcascode (RGC) circuit [22,23,24,25] is widely used for a wideband TIA because it has a low-input impedance characteristic, and various modified RGC circuits are investigated [26,27]. For more reducing the input impedance, a CR-RGC TIA using a current-reuse (CR) technique [28] based on the RGC TIA has been proposed [16].…”