Ultra‐low power TIA with variable bandwidth in 0.13 μ m 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 0.13 μ m 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 mm 2 with pads and 0.1 × 0.1 mm 2 without pads.