Ultra‐low power TIA with variable bandwidth in 0.13um CMOS for short‐range optical interconnects

An ultra‐low power and variable bandwidth transimpedance amplifier (TIA) for short‐range optical interconnects is presented here. The TIA is implemented in a 0.13m complementary metal oxide semiconductor (CMOS) technology. To reduce the power consumption, the TIA is designed using a regulated cascade topology with capacitor degeneration for frequency enhancement and also operates in the weak inversion mode. With a supply voltage of the range 0.7–0.92 V, a reduced power consumption of 2.9–4.6 mW and a variable bandwidth of the range 3–4.9 GHz are achieved. Clear eye diagrams are obtained at 2.5–6.135 Gbps and a BER of less than 10−12 with input power of −4.3 to −3 dBm at 2.5–6.135 Gbps, respectively. Also, the TIA achieved a transimpedance gain of 51.2–52.4 dBΩ. The small‐sized chip occupied an area of 0.28 × 0.42 mm2 with pads and 0.1 × 0.1 mm2 without pads.