High Accuracy Digital to Analog Converter Based on Processing Magnetic

HYPRES proposes the development of Digital-to-Analog Converter (DAC) with extremely high accuracy and linearity. The DAC is based on the processing of magnetic flux quanta in an integrated superconductive circuit. The device uses a stable reference ac signal at relatively low frequency (below 100 MHz). This frequency is multiplied on chip up to 48 GHz. The operation of the device is based on the digital replication of Single Flux Quantum (SFQ) pulses with an integer (or fractional) factor proportional to the digital input code. Each of these pulses is applied to one of a series of output stages, such that the output voltage is proportional to the input code. Due to the fundamental Josephson voltage-to-frequency relationship, this proportionality is absolutely accurate, and results in extremely high linearity. The precision of the conversion would be limited only by the stability of the external reference signal. For HYPRES' 3.5 mm 1 kA/cm2 all-niobium technology the proposed device will operate with a 3 GHz sampling rate. Phase 1 will establish the feasibility of the new design we propose, by demonstrating all parts of the DAC working separately and a 8-bit DAC. Phase 2 will lead to a multi-chip DAC with 16-bit dynamic range at a 3 GHz sample rate.