Title :
On the Noise Optimum of FET Broadband Transimpedance Amplifiers
Author :
Säckinger, Eduard
Author_Institution :
Ikanos Commun., Inc., Red Bank, NJ, USA
Abstract :
The optimum sizing of the front-end FET in transimpedance amplifiers (TIA) is revisited. Analytical solutions based on a second-order shunt-feedback TIA model that includes the feedback-resistor noise are derived. It is shown that the optimum FET size can be smaller or larger than suggested by the well-known capacitive matching rule, depending on whether the noise optimization is carried out under a constant gain-bandwidth-product constraint or a constant load-capacitance constraint.
Keywords :
circuit feedback; circuit optimisation; field effect transistors; operational amplifiers; wideband amplifiers; FET broadband transimpedance amplifiers; capacitive matching rule; constant gain-bandwidth-product constraint; constant load-capacitance constraint; feedback-resistor noise; front-end FET; noise optimization; second-order shunt-feedback TIA model; Bandwidth; Capacitance; FETs; Load modeling; Logic gates; Noise measurement; Resistors; Field effect transistor; low-noise amplifiers; noise bandwidth; optical communication systems; transimpedance amplifiers;
Journal_Title :
Circuits and Systems I: Regular Papers, IEEE Transactions on
DOI :
10.1109/TCSI.2012.2206452
