A 10 Gb/s noise-canceled transimpedance amplifier for optical communication receivers

This study presents a noise-canceled transimpedance amplifier (TIA) for optical receivers. The proposed structure consists of a shunt feedback common source amplifier as an input stage followed by two regulated cascodes (RGC) and finally a differential to the single-ended amplifier at the output stage. By exploiting the noise-canceling technique at the input stage, 31.8% of the total output noise is canceled. In addition, the auxiliary path's RGC circuit, as it has a low input impedance, is utilized to cancel out the photodiode (PD) large parasitic capacitance at the input stage. The proposed TIA along with post amplifiers, including packaging components, are simulated in TSMC 90 nm RF CMOS technology at the post-layout level. The TIA average input-referred current noise is equal to 9.5 pA/root Hz. The PD capacitance is considered as 325 fF for all simulations. The transimpedance gain is equal to 60 dB Omega and the 3-dB bandwidth is equal to 7 GHz. The power consumption of the proposed TIA is 3.6 mW from a 1.2 V supply voltage. The TIA occupies a chip area of 0.036 mm(2).