Custom design of a fully digital true random number generator in 65-nm CMOS technology

The random number generator (RNG) is an essential component for a wide range of applications. These structures, which have been used for many years, are being developed day by day. It is one of the indispensable structures in computers and smart devices, especially in today's digital world. Many design applications, games, simulation programs, password generator programs, protected communication protocols need an RNG. RNGs are generally investigated in two different categories. The first type, pseudo-random number generator (PRNG), is often software-based and works with a deterministic algorithm. It is preferred in applications that do not require security because it can be designed easily and generate random numbers with excellent statistical properties. The second type, true random number generator (TRNG), is often used for cryptographic applications. One of the most important features to look for in the TRNG is that it produces a truly unpredictable random number sequence. Therefore, it needs a non-deterministic natural source. TRNGs use an entropy source that uses physical phenomena to meet this requirement. In this study, a custom TRNG design is presented using 65-nm CMOS technology. This design is based on metastability and is created by adding digital blocks to a structure with a dynamic comparator topology. The aim of the design is to create a circuit with a high entropy value, low power consumption, and high throughput in a small footprint as possible. It has been validated with simulations at different technology-voltage-temperature (PVT) corners to ensure that the designed circuit can operate in different conditions.