Title :
Dynamics of a Logarithmic Transimpedance Amplifier
Author :
Basu, Arindam ; Odame, Kofi ; Hasler, Paul
Author_Institution :
Sch. of Electr. & Comput. Eng., Georgia Inst. of Technol., Atlanta, GA
Abstract :
We analyze the dynamics of a logarithmic transimpedance amplifier that are not explainable from its small-signal model. The amplifier was used both to measure pixel currents in an imager as well as currents from a floating gate array for accurate programming. We explain the marked asymmetry between the up-going and down-going current steps intuitively using circuit concepts and then based on phase-plane analysis. This analysis also helps develop a method of reducing the huge delay to down-going current steps.
Keywords :
network analysis; operational amplifiers; floating gate array; logarithmic transimpedance amplifier; marked asymmetry; phase-plane analysis; pixel current measurement; small-signal model; Bandwidth; Circuits; Current measurement; Delay; Differential amplifiers; Diodes; Feedback; MOS devices; Pixel; Voltage;
Conference_Titel :
Circuits and Systems, 2007. ISCAS 2007. IEEE International Symposium on
Conference_Location :
New Orleans, LA
Print_ISBN :
1-4244-0920-9
Electronic_ISBN :
1-4244-0921-7
DOI :
10.1109/ISCAS.2007.377914
