A transimpedance amplifier (TIA), using the combination of the shunt-feedback topology with the regulated-cascode input stage and broadband matching network, is designed and implemented in a 0.13-mu m CMOS technology. The proposed TIA achieves a 3-dB bandwidth of 7.5 GHz, transimpedance gain of 50 dB Omega in the presence of 300 fF photodiode capacitance. It dissipates 4.1 mW from a 1.2 V supply voltage, and occupies a chip area without pads of 0.42 x 0.17 mm(2). The TIA presents the highest gain-bandwidth product per DC power figure of merit of 578 GHz Omega/mW compared with recently published TIAs. (C) 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:448-451, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25741