NIST SP 800-90B Compliant Perpendicular Magnetic Tunnel Junction Based True Random Number Generator

True random number generators (TRNGs) are essential for applications such as hardware security and cryptographic protocols. Magnetically stabilized spin-transfer torque-perpendicular magnetic tunnel junctions (STT-pMTJs) have emerged as a promising candidate for TRNGs due to their rapid switching speed and low energy consumption. The switching speed could be controlled by the voltage amplitude, enabling high-quality bit generation with adjustable frequency. In previous studies, the quality of the generated bits is evaluated by NIST 800-22 standards, which are now considered outdated and insufficient for modern cryptographic requirements. In this work, we demonstrate a pMTJ-based TRNG with a low resistance-area (RA) product of 3.5 Ω•μm² and a tunnel magnetoresistance (TMR) ratio of 105%. Magnetization switching occurs in 2.70 ns with a probability of 50% at a current density of 3.38×10 A/cm². The generated bits achieve NIST SP 800-90B compliance with only a single XOR whitening step.