A True-Random-Number-Based Pseudohysteresis Controller for Buck DC–DC Converter in High-Security Internet-of-Everything Devices

For high-security Internet-of-Everything (IoE) devices, a true random number (TRN)-based pseudohysteresis controller (PHC) is proposed to avoid both power side-channel attack (PSCA) and power injection attack (PIA) and reduce electromagnetic interference (EMI) without degrading performance of transient response and regulation. In addition, the TRN-based PHC uses an enhanced security randomizer to correctly generate a random number (RN) independent of the input power at the PSCA and PIA and converts the RN into a hysteresis window that constitutes the true random modulation switching frequency. Therefore, the TRN-based PHC ensures proper spread spectrum and low EMI. In addition, fast transient response is maintained due to inherent hysteresis control. Experimental results show that peak EMI noise is reduced from 89.72 to 54.32 dBμV and meets the specification of EN 55032 Class B even under the PIA interference up to 1 V. Furthermore, in case of 0.2 A-to-0.8 A load step, the method achieves a recovery time of 7.3 μs and an output voltage drop of 53 mV at a switching frequency of approximately 1 MHz, and the peak efficiency is 92.4%.