A low power 3.125Gbit/s/channel parallel optical receiver for Very Short Reach (VSR) applications

A truly-differential transimpedance amplifier (TIA) for optical receiver front-ends based on common-gate topology is fabricated and tested. -16dBm sensitivity is achieved for this inductorless TIA at 3.125Gbit/s while drawing 3.7mA current from a 1.2V power supply. The channel power consumption is 22mW including an input buffer (IB), a limiting amplifier (LA), and a current-mode-logic (CML) output buffer with a 400mV peak-to-peak differential output swing. We present a method to convert pseudo-differential signals into truly-differential signals by using AC coupling techniques. Also a new method of measuring cross-talk power penalty with an on-chip pseudo-randotii-bit-sequence (PRBS) generator is introduced. The circuits are implemented in the IBM CMRF8SF-DM 0.13-mu m complementary-metal-oxide-semiconductor (CMOs) process.