Title :
Two novel cross-cascode differential amplifiers
Author :
Bruck, Y. ; Zelikson, M.
Author_Institution :
High Speed Circuit Dept., Haifa Univ., Israel
Abstract :
Two novel cascode circuits, the differential cross-cascode and differential cross-follower, are proposed and investigated. Their fundamental distinction from the differential ordinary cascode consists of the input signal voltage being applied simultaneously to the inputs of common emitter/source and common base/gate stages, and in addition the inputs of CE/CS and CB/CG are cross-coupled. We show that the input signal is amplified in the input circuit, and furthermore the input impedance and the current gain increase considerably and the bandwidth is essentially expanded. Simulation results of such a cascode designed with IBM BJT and FET transistors are presented. The actual obtained bandwidths (BJT-18.7 GHz, FET-7.8 GHz) proved as predicted to be more than twice as wide as compared with the bandwidth of the ordinary cascode (BJT-8.6 GHz, FET-3.4 GHz).
Keywords :
CMOS analogue integrated circuits; bipolar analogue integrated circuits; circuit simulation; coupled circuits; differential amplifiers; electric impedance; integrated circuit design; integrated circuit modelling; 18.7 GHz; 3.4 GHz; 7.8 GHz; 8.6 GHz; CE/CS CB/CG cross-coupled inputs; CMOS-based cascodes; IBM BJT cascode design; IBM FET cascode design; amplified input signal; cascode circuits; common base/gate stage; common emitter/source stage; cross-cascode differential amplifiers; current gain; differential cross-cascode; differential cross-follower; expanded bandwidth; input impedance; input signal voltage; simulation; Bandwidth; Character generation; Circuit simulation; Differential amplifiers; FETs; Frequency; Impedance; Laboratories; Research and development; Voltage;
Conference_Titel :
Electronics, Circuits and Systems, 2004. ICECS 2004. Proceedings of the 2004 11th IEEE International Conference on
Print_ISBN :
0-7803-8715-5
DOI :
10.1109/ICECS.2004.1399602
