An oscillator-based true random number generator with process and temperature tolerance

This paper presents an oscillator-based true random number generator (TRNG) that automatically adjusts the duty cycle of a fast oscillator to 50 %, and generates unbiased random numbers tolerating process variation and dynamic temperature fluctuation. Measurement results with 65nm test chips show that the proposed TRNG adjusted the probability of `1' to within 50 ± 0.07 % in five chips in the temperature range of 0 °C to 75 °C. Consequently, the proposed TRNG passed the NIST and DIEHARD tests at 7.5 Mbps with 6,670 μm
²
area.