Cryogenic low-dropout voltage regulators for stable low-temperature electronics

To enable scalable quantum computers, it has been proposed that the quantum–classical interface has to be integrated and operated at deep-cryogenic temperatures. Common to all electronics is the power management and distribution through the system. These systems are currently powered from room temperature supplies, thus requiring long interconnects. This results in a significant and fluctuating voltage drop from the supply to the electronics. Especially sensitive systems, such as analog-to-digital and digital-to-analog converters that are needed for the read-out and control of the quantum processor, are thus limited in performance by the stability of the voltage regulation at room temperature. In this paper, we propose the design and use of voltage regulators at cryogenic temperatures (down to 4 K), close to the actual load. As no commercial regulator was found to work below 90 K, we implemented an ad hoc low-dropout regulator with commercially available components that operate at 4 K. Its output voltage varies with less than 0.2% over the complete temperature range and it can regulate loads within 1 mV/A.