6-kΩ 43-Gb/s differential transimpedance-limiting amplifier with auto-zero feedback and high dynamic range

A high-gain, 43-Gb/s InP HBT transimpedance-limiting amplifier (TIALA) with 100-μA_pp sensitivity and 6 mA_pp input overload current is presented. The circuit also operates as a limiting amplifier with 40-dB differential gain, better than 15-dB input return loss, and a record-breaking sensitivity of 8 mV_pp at 43 Gb/s. It features a differential TIA stage with inductive noise suppression in the feedback network and consumes less than 450mW from a single 3.3-V supply. The TIALA has 6-kΩ (76dBΩ) differential transimpedance gain and 35-GHz bandwidth and comprises the transimpedance and limiting gain functions, an auto-zero dc feedback circuit, signal level monitor, and slicing level adjust functions. Other important features include 45-dB isolation and 800-mV_pp differential output.