Low-noise optimisation of current-mode, common-gate transimpedance optical preamplifiers

The most significant figure of merit of a transimpedance preamplifiers in fibre-optics systems is the sensitivity which is determined by the equivalent input noise current of the preamplifier. The FET input-stage preamplifier may be designed for optimum sensitivity by choosing a proper FET size for a given photodiode capacitance. The optimum FET size for a current-mode common-gate transimpedance preamplifier is described.<
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