Low power transimpedance amplifier using current reuse with dual feedback

Abstract

This paper presents a transimpedance amplifier (TIA) topology employing current-reuse technique to achieve low power operation. A dual feedback is employed in addition to the current-reuse (CRDF-TIA) to extend the bandwidth while keeping the low power consumption. For large area photodiodes with 2 pF total input capacitance the CRDF-TIA post layout simulation shows a transimpedance gain of 56.75 dBQ and 2 GHz bandwidth. The CRDF-TIA shows a 835nA input-referred noise current and a sensitivity of −22.3 dBm at BER of 10−12. An analytical noise model is derived showing a good accuracy compared to the simulated results. An optical receiver employing the proposed TIA as preamplifier is implemented in 130nm CMOS technology. The TIA is followed by post amplifier and 50 Ω output driver. The complete optical receiver achieves 85.2dBΩ and 1.6 GHz bandwidth. The CRDF-TIA alone consumes 2.85 mW from 1.5 V power supply and the total power consumption of the chip is 29.4 mW.