Design of a CMOS Optical Receiver Front-End Using 0.18 μm Technology

Ajay Shukla,Radheshyam Gamad,Rohan Raikwar

doi:10.4236/wet.2013.41007

Abstract

This paper reports design of a CMOS optical receiver front-end using 0.18 μm technology. Design process is current associated with photodiode using trans-impedance amplifier (TIA) for wide bandwidth, high gain, low input referred noise and wide dynamic range. The Automated Gain Control (AGC) voltage is used to provide variable gain for multilevel signals. This design is simulated in 0.18 μm UMC technology for the performance analysis. The best simulation results are reported the maximum TIA gain of 67.26 dB? at 0 V AGC followed by a post amplifier gain of 86.70 dB?. The bandwidth range is 7.03 GHz to 11.5 GHz corresponding to 0 - 3 V AGC respectively. The input referred noise level value is 43.86 pA/√Hz up to 10 GHz frequency. In addition authors have obtained the common mode rejection ratio (CMRR) is 72.42 dB and rectified group delay is 144.48 ps. Verification of the design, reported results are compared with earlier published work and improvements obtained in the present results.

Highlights

Optical receivers find applications in laptop computers, cellular phones, digital cameras, computer peripherals, personal digital assistants (PDAs), and many other consumer electronics equipped with a short-distance communication port
This paper reports design of a CMOS optical receiver front-end using 0.18 μm technology
In this the current at two differential inputs I6 and C1 is converted into the voltage forms using the trans-impedance amplifier

Summary

Introduction

Optical receivers find applications in laptop computers, cellular phones, digital cameras, computer peripherals, personal digital assistants (PDAs), and many other consumer electronics equipped with a short-distance communication port. A commonly used topology is the transimpedance (TIA) amplifier, whose relative low input impedance and wide bandwidth is well suited for the application [1]. A wide dynamic range is required for infrared wireless optical receivers in order to accommodate variable link distances, 0 ~ 100 cm. In the design of fixed-gain trans-impedance feedback amplifiers for infrared wireless receivers, there is a direct trade-off between input noise current and the input current overload level via the value of the shunt feedback resistor employed. In order to enlarge the dynamic range, various means have been adopted to vary the gain of the trans-impedance amplifiers in response to the input signal levels. The TIA uses an AC coupled, differential version of the low-voltage topology outlined in [4], which is modified common-gate architecture.

Methods

Results

Conclusion