Abstract
Abstract The work reports on the design and performance of a low-noise low-cost CMOS transimpedance amplifier (TIA). The proposed circuit shall be employed in optical time-domain reflectometers and is implemented using an affordable 0.18 µm 1.8 V CMOS process. The approach preserves the benefits of a classical feedback structure while addressing the noise problem of conventional feed-forward and resistive feedback architectures via the usage of noise-efficient capacitive feedback. Circuit-level modifications are proposed to mitigate the voltage headroom and DC current issues. The suggested design achieves a total gain of 82 dBΩ (79 dBΩ after the output buffer) within the bandwidth of 1.2 GHz while operating with a total input capacitance of 0.7 pF. The simulated average input-referred noise current density is below 1.8 pA/sqrt(Hz) with the power consumption of the complete amplifier including the output buffer being 21 mW.
Highlights
The constantly increasing requirements for available data rates and even larger capacities in communication systems have led to wide adoption of optical data transmission systems
The post-layout simulation results for the transimpedance gain and the input-referred noise currents are shown in Fig. 5 and Fig. 6 correspondingly
A tremendous growth of the market for optical communication systems, when compared to niche Optical Time-Domain Reflectometry (OTDR), caused a large number of Complementary Metal-Oxide-Semiconductor (CMOS) transimpedance amplifier (TIA) designs proposed in the last decades
Summary
The constantly increasing requirements for available data rates and even larger capacities in communication systems have led to wide adoption of optical data transmission systems. The intensive deployment of the required infrastructure boosted interest in the related instrumentation and maintenance equipment for network monitoring and repairs. The tools based on Optical Time-Domain Reflectometry (OTDR) [1] are one of the typical instruments for characterization of the optical fiber links. The precise location and the nature of the problem in the fiber can be resolved from an accurate time-domain measurement of the reflected optical pulse. The technique works, first by injecting a series of relatively narrow optical pulses to the fiber and monitoring the properties of the reflected signals caused by the Rayleigh Backscattering or Fresnel reflections. The analysis of the reflected signal allows estimation the general dependency of the fibre loss characteristics on the length of the fiber, and permits detection of major faults and identification of their types by observing the properties of the reflected signals (timing, amplitude, etc.) at the input of the very same fiber
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
