Title :
A transmission-line approach for modeling feedback resistors in integrated transimpedance amplifiers
Author :
Knorr, Johannes ; Zimmermann, Horst
Author_Institution :
Kapsch AG, Vienna, Austria
Abstract :
Based on the transmission-line model, the grounded uniformly distributed RC line (URC) is used to investigate the behavior of the feedback resistor used in transimpedance amplifiers (TIAs). Due to their strong capacitive coupling to substrate ground, polysilicon resistors used in the feedback circuit contribute to the frequency response of the overall amplifier. This may result in limitations in bandwidth, signal distortion and even instability. A simple and descriptive model is derived to find design formulas to optimize the overall amplifier including its feedback capacitor and to show an upper performance limit for an idealized amplifier with high gain. Simulation results based on the approximation model and on the exact URC model are delivered for both an idealized as well as for a real amplifier.
Keywords :
circuit optimisation; circuit stability; equivalent circuits; feedback amplifiers; frequency response; integrated circuit design; integrated circuit modelling; integrated optoelectronics; linear network analysis; monolithic integrated circuits; silicon; step response; thin film resistors; transmission line theory; wideband amplifiers; OEIC; Si; approximation model; design formulas; exact URC model; feedback capacitor; feedback circuit; feedback resistor; frequency response; grounded uniformly distributed RC line; integrated transimpedance amplifiers; optoelectronic integrated circuit; photodiode capacitance; polysilicon resistors; transmission-line model; Bandwidth; Capacitors; Coupling circuits; Design optimization; Distortion; Distributed amplifiers; Feedback circuits; Frequency response; Resistors; Transmission lines;
Journal_Title :
Circuits and Systems I: Fundamental Theory and Applications, IEEE Transactions on
DOI :
10.1109/TCSI.2003.816322
