Title :
Experimental implementation of SFQ NDRO cells and 8-bit ADC
Author :
Kaplunenko, V.K. ; Khabipov, M.I. ; Khokhlov, D.Yu. ; Kirichenko, A.F. ; Koshelets, V.P. ; Kovtonyuk, S.A.
Author_Institution :
Inst. of Radio Eng. & Electron., Moscow, Russia
fDate :
3/1/1993 12:00:00 AM
Abstract :
Two single-flux quantum (SFQ) logic elements have been designed, fabricated, and successfully tested: an 8 b analog-to-digital converter (ADC) and nondestructive readout (NDRO) cells. The converter consists of an input coil, a comparator, and a reversible ripple counter. The ADC shows a good linearity (+or-12 mA) and a quite high calculated frequency range (up to 2.5 GHz). Two types of input coils differing in inductance and two types of NDRO units also have been investigated: with direct and magnetic coupling between interferometers. The integrated circuits are fabricated using 4 mu m Nb-AlO/sub x/-Nb trilayer technology with a critical current density of about 1000 A/cm. This techniques makes it possible to produce NDRO cells operating up to 10 GHz frequency.<>
Keywords :
SQUIDs; analogue-digital conversion; critical current density (superconductivity); nondestructive readout; superconducting integrated circuits; superconducting logic circuits; 10 GHz; 2.5 GHz; 4 micron; 8-bit ADC; A/D convertor; NDRO cells; Nb-AlO/sub x/-Nb trilayer technology; SFQ logic elements; analog-to-digital converter; comparator; critical current density; eight bit convertor; input coil; integrated circuits; interferometers; magnetic coupling; nondestructive readout; reversible ripple counter; single-flux quantum; Analog-digital conversion; Coils; Counting circuits; Coupling circuits; Frequency; Inductance; Linearity; Logic design; Logic testing; Nondestructive testing;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
