A 0.012mm² Inverter-Based Ring-Oscillator with Power-Supply Voltage Noise Isolator for Quantum Applications in 22-nm FD-SOI CMOS

In this paper, we present an inverter-based ring oscillator (RO) operating at cryogenic temperatures for quantum computing applications. It employs a low-dropout regulator (LDO) to provide supply voltage for a programmable switched-capacitor system which isolates the supply line of the integrated RO circuit from any noise or perturbations of the external power supply. In anticipation of embedding the RO into a phase-locked loop (PLL), we study the variation of flicker phase noise from cryo to room temperature by indirectly measuring the phase noise (PN) in the 30dB/dec region. The proposed system occupies 0.012mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and shows 3.5dB integrated PN improvement thanks to the proposed voltage supply noise reduction technique at room temperature (RT) and the FOM is estimated as 121.7dB at cryogenic temperature (CT).