13 Gb/s Si-bipolar AGC amplifier IC with high gain and wide dynamicrange for optical-fiber receivers

A complete linear automatic-gain-control (AGC) amplifier for a 10 Gb/s optical-fiber link was integrated on a single chip, using a Si-bipolar production technology with f_T≈22 GHz. It is characterized by a high gain of 37 dB, linear operation over a wide input dynamic range of 47 dB, a maximum data rate of 13 Gb/s, and a gain-independent 3-dB cut off frequency of 10 GHz. The circuit consumes 850 mW at a single supply voltage of -6.5 V. It can be operated in both a single-ended and differential mode. A novel 50-Ω input matching circuit with only small return loss is used. Two separate output buffers with a constant output voltage swing of 500 mV_p-p allow splitting up the output signal without use of external components