CMOS transimpedance amplifier for biosensor signal acquisition

Ibrahim, Mark. M.R.; Levine, Peter M.

doi:10.1109/iscas.2014.6865056

Cited by 8 publications

(2 citation statements)

References 26 publications

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“…Moreover, such a large feedback resistor cannot be reliably realized on-chip and must be externally connected. A high-value active pseudo resistor made using off-state transistors have been widely used for small current sensing [5][6][7][8]. However, the resistance is inversely proportional to the input current, which leads to a variable current gain and bandwidth applications [9].…”

Section: Introductionmentioning

confidence: 99%

An Approach for a Wide Dynamic Range Low-Noise Current Readout Circuit

Wang

Sonkusale

2020

JLPEA

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Designing low-noise current readout circuits at high speed is challenging. There is a need for preamplification stages to amplify weak input currents before being processed by conventional integrator based readout. However, the high current gain preamplification stage usually limits the dynamic range. This article presents a 140 dB input dynamic range low-noise current readout circuit with a noise floor of 10 fArms/sq(Hz). The architecture uses a programmable bidirectional input current gain stage followed by an integrator-based analog-to-pulse conversion stage. The programmable current gains setting enables one to achieve higher overall input dynamic range. The readout circuit is designed and in 0.18 μm CMOS and consumes 10.3 mW power from a 1.8 V supply. The circuit has been verified using post-layout simulations.

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Section: Introductionmentioning

confidence: 99%

An Approach for a Wide Dynamic Range Low-Noise Current Readout Circuit

Wang

Sonkusale

2020

JLPEA

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“…Usually, front-end TIAs for optical sensing are designed using a shunt-feedback [7][8][9], or a current-mode [10] topology. Some of the basic requirements for a TIA design are high gain, good linearity, low-noise and sufficient bandwidth for amplifying a range of biological signals.…”

Section: Introductionmentioning

confidence: 99%

Design of a low-current shunt-feedback transimpedance amplifier with inherent loop-stability

Mathew

Hart

Hayatleh

2019

Analog Integr Circ Sig Process

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In this paper we propose a new architecture for enhancing the performance of a transimpedance amplifier (TIA) used for low-currents, and in particular, that used in biosensing. It is usually the first block in biomedical acquisition systems for converting a current in the nanoampere and picoampere range into a proportional voltage, with an amplitude suitable for further processing. There exist two main amplifier topologies for achieving this, current-mode and shunt-feedback mode. This paper introduces a shuntfeedback amplifier that embodies current-mode operation and thereby offers the advantages of both existing schemes. A conventional shunt-feedback amplifier has a number of stages and requires compensation components to achieve stability of the feedback loop. The exemplary circuit described is inherently stable because a high gain is effectively achieved in one stage that has a dominant pole controlling the frequency response. Exhibiting complementary symmetry, the configuration has an input port that is very close to earth potential. This enables the configuration to handle bidirectional input signals such are as met with in electrochemical ampero-metric biosensors. For the 0.35µm process adopted and ±3.3V rail supplies, the power dissipation is 330µW. With a transimpedance gain of 120dBohm the incremental input and output resistances are less than 2ohm and the-3dB bandwidth for non-optical input currents is 8.2MHz. The input referred noise current is 3.5pA/√Hz.

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