Design and implementation of cryogenic semiconductor amplifiers as interface between RSFQ circuits.pdf

Cryogenics 49 (2009) 652–655 Contents lists available at ScienceDirect Cryogenics journal homepage: www.elsevi /locate/cryogenics Design and implementation of cryogenic semiconductor amplifiers as interface between RSFQ circuits S. Wuensch a,*, T. Ortlepp b, M. Schubert c, E. Crocoll a, G. Wende c, H.-G. Meyer c, F.H. Uhlmann b, M. Siegel a a Institute for Micro- and Nanoelectronic Systems, University Of Karlsruhe (TH), Hertzstrasse 16, 76187 Karlsruhe, Germany b Institute of Information Technology, Ilmenau University of Technology, P.O. Box 100565, 98684 Ilmenau, Germany c Institute of Photonic Technology, P.O. Box 100239, 07702 Jena, Germany a r t i c l e i n f o a b s t r a c t Article history: Rapid single flux quantum (RSFQ) circuits create high interest in cryogenic amplifiers as interface to Received 31 July 2008 commercial room temperature electronics. The requirements for the amplifiers are an extremely high Received in revised form 4 December 2008 4 bandwidth (SFQ pulses with trise ¼ tfall ¼ 10 ps), high voltage gain of about 10 (common RSFQ output Accepted 27 December 2008 voltage level of about 200 lV), low power consumption (cryogenic environment at 4 K) and low noise. Hybrid amplifiers, based on commercial available p-HEMT transistors, can solve the problematic high-