NAND‐Structured Physically Unclonable Function With Current Mirror Switching Stabilization and Minimized CRP Discards
Hyungwoo Kim, Dong‐Woo Jee, Jongmin Lee · Electronics Letters · 2025
ABSTRACT This paper presents a NAND‐structured physically unclonable function (PUF) incorporating a novel current mirror‐switching stabilization scheme. The proposed design leverages sub‐threshold current mismatches induced by process variations to generate random responses. To address scenarios where the current difference is insufficient for stable response generation, the current mirror‐switching method amplifies the mismatch, thereby enhancing stability and reducing the number of discarded challenge‐response pairs (CRPs) through trimming. Simulation results demonstrate that the proposed PUF achieves the worst‐case bit flip ratio (BFR) 0.99% at 1.8 V and 80 with 1.64% trimming ratio. By applying the proposed current mirror switching method, the trimming ratio is reduced by 86.2% while maintaining equivalent reliability. Furthermore, the proposed PUF achieves robust BFR performance, with variations of 0.099% per 10 and 0.071% per 100 mV under temperature and supply voltage changes, respectively.