| Popis: |
A performance optimized transimpedance amplifier (TIA) has been designed and fabricated for up to 3 Gb/s NRZ optical links. The amplifier is based on a standard foundry BiCMOS technology which utilizes 0.8 /spl mu/m BJT emitter width and poly-Si capacitors and resistors. It exhibits a transimpedance gain of 62 dB/spl Omega/ over the -3 dB bandwidth of DC-1.7 GHz and a DC power consumption of 137 mW when biased at +5 V and being AC coupled to the load. The equivalent input noise current density is 9.8 pA//spl radic/Hz (including the contribution of the 0.5 pF photodiode) for the bandwidth of 1.7 GHz and the input optical sensitivity is -23.3 dBm at a BER=10/sup -9/ In addition, the electrical dynamic range is 49.6 dB, when a 1 V output signal is considered, and it was designed to be unconditionally stable with a relatively large tolerance on external bias conditions. The circuit represents the first reported TIA, which combines such features, using conventional 0.8 /spl mu/m BiCMOS transistors with f/sub T/=12 GHz and f/sub MAX/=4 GHz. |
