Abstract
A new wideband high gain CMOS transimpedance amplifier is presented without using any inductor. In the proposed TIA, gain enhancing path is introduced in the active voltage-current feedback TIA topology to increase both the gain and bandwidth. This path increases the transconductance of the proposed TIA which reduces the input resistance and leads to bandwidth extension. Additionally, for utilizing the benefit of this topology, cascading of common source stage is also done to increase the gain further without deteriorating the bandwidth. Mathematical analysis is also performed to evaluate both the gain and bandwidth enhancement. These analyses are supported by simulations that are done using TSMC 0.18 µm CMOS technology with the input photodiode capacitance of 0.3 pF. The proposed TIA occupies 0.019 mm2 area and consumes 3.2 mW from 1.8 V supply voltage. The transimpedance gain of the proposed TIA is found to be 57.15 dBΩ over the bandwidth of 6.5 GHz. The input noise is 17.16 pA/√Hz.
Highlights
The significant increase in the demand of high data rates has motivated researchers to explore optical communication systems that are suitable to handle this requirement
Various bandwidth enhancement techniques are reported such as inductive peaking [5,6], capacitive degeneration [7,8], capacitive feedback [9,10], negative capacitance [11], common gate (CG) [12] and regulated cascode (RGC) [13,14]
The Transimpedance amplifier (TIA) circuit based on active voltage-current feedback topology is shown in Fig. 1 in which transistor M1 provides feedback path and decreases the output and input resistances [15]
Summary
The significant increase in the demand of high data rates has motivated researchers to explore optical communication systems that are suitable to handle this requirement. Various bandwidth enhancement techniques are reported such as inductive peaking [5,6], capacitive degeneration [7,8], capacitive feedback [9,10], negative capacitance [11], common gate (CG) [12] and regulated cascode (RGC) [13,14] Both the inductive and capacitive compensation increase the bandwidth but they occupy the large chip area. RGC is the most common topology to design TIA due to its low input impedance, high stability and wide bandwidth but it has higher power dissipation and headroom voltage. Active voltage-current feedback TIA topology [15] is used which provides low input and output impedances. In this topology, thegain enhancing pathis introduced insuch a way that it increases both gain and bandwidth.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
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
