A 12.5 Gb/s 0.13‐μm CMOS inductorless transimpedance amplifier with 1 pF input capacitance for optical communications

SummaryThe present study is devoted to articulating a modified folded‐cascode circuit, to make folded‐cascode structures an attractive configuration as a transimpedance amplifier (TIA) for being employed in Giga‐bit per second optical communication receiver systems. Giga‐bps communication receivers are highly necessitating circuits to isolate the input parasitic capacitance of the photodiode. The present modification makes folded cascodes comparable to the famous regulated cascode (RGC) structures by isolating this parasitic capacitor almost by the same quantity. The system is shown to be capable of operating at 2.5 Gbps up to 8 Gbps data rate with a fixed bandwidth. The paper analyzes and evaluates the designed circuit mathematically, and the obtained simulated results from Cadence using TSMC 65 nm CMOS validate the suitability of the modified circuit as a TIA.

Section: The Proposed Tiamentioning

confidence: 99%

Section: The Proposed Tiamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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An improved low‐input resistance folded‐cascode transimpedance amplifier for giga‐bit per second optical communication front‐ends

Zohoori,

Hosseini,

Dehkordi

et al. 2023

“…Modified versions of the RGC structure have been proposed to overcome the headroom limitation and provide lower input impedance. [8][9][10][11][12][13][14] The other common topology to reduce the input impedance is to use the cross-coupled structure. 15 This structure is shown in Figure 1C.…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, limited headroom is available for the effective voltage of M 2 or voltage drop across R D . Modified versions of the RGC structure have been proposed to overcome the headroom limitation and provide lower input impedance 8–14 …”

Section: Introductionmentioning

confidence: 99%

Employing bias current feedback in MIC transimpedance amplifier to increase bandwidth

Sohrabi,

Behnazar

2023

SummaryThis paper presents an inductorless transimpedance amplifier (TIA) that employs bias feedback technique in a MOS‐based immittance converter (MIC) to achieve high bandwidth. The bias feedback technique is analyzed and explored as a supplementary approach to reduce the input impedance in a current buffer structure. Employing this technique in a MIC‐based TIA structure provides an additional degree of freedom for the design and helps reduce the trade‐off between bandwidth and power. The proposed structure is designed and simulated in 0.18 μm CMOS technology considering a 1 pF photodiode capacitance. The post‐layout simulation results show that the TIA provides a transimpedance gain of 50.9 dBΩ, a bandwidth of 6.1 GHz, and an input‐referred current noise of 9.9 pA/√Hz. The circuit consumes 3.42 mW from a 1.8 V supply and occupies 0.0046 μm2 area. Results are compared with TIAs reported in the literature, which confirms the effectiveness of the proposed modified MIC structure.

Design of a Novel CMOS Transimpedance Amplifier Based on a Current Mirror

Shaaban,

Sharroush,

Abdalla

et al. 2024

The transimpedance amplifier (TIA) is an essential component in optical communication systems. It converts the photodiode current to a voltage for further processing. In this paper, a novel CMOS current‐mirror‐based TIA is proposed. Its suitability to optical communication systems is verified. The current‐mirror topology is chosen due to its low input resistance and highly linear current amplification. The proposed TIA employs negative feedback and shunt‐inductive peaking to extend the bandwidth. Three configurations of the shunt‐inductive peaking are explored: one with passive inductors and two with active inductors. The proposed TIA is verified by simulation using the 45‐nm CMOS technology with a 1‐V supply and 1‐pF photodiode capacitance with the key performance trade‐offs discussed. A figure of merit (FoM) is introduced to evaluate the performance of the proposed TIA. The simulation results of the proposed TIA with passive inductors show a gain of 30.6 dB, a 3‐dB bandwidth of 2.8 GHz, and a power consumption of 1.63 mW, with an input‐referred noise current of 23.55 pA/√Hz.