JOSEPHSON D A CONVERTER WITH FUNDAMENTAL ACCURACY/

A binary sequence of series arrays of shunted Josephson junctions is u sed to make a 14-b D/A converter. With 13 bias lines,any step number i n the range -8192 to +8192 -1.2 V to +1.2 V can be selected in the tim e required to stabilize the bias current (a few microseconds). The cir cuit is a fast accurate de reference, and it makes possible the digita l synthesis of ac waveforms whose amplitudes derive directly from the internationally accepted definition of the volt.