Monolithic Quantum Random Number Generator Containing Si-LED, SPAD and Analog Processing

Abstract

This work describes a monolithically integrated photonic quantum random number generator (QRNG) in 0.35µm CMOS. This QRNG consists of a light-emitting diode inside a deep N-well, a ring single-photon avalanche diode (SPAD), a fast cascoded active quenching and resetting circuit, and an analog evaluation circuit determining whether the random bit is a ”0” or ”1”. The random bits are created by comparison of two consecutive time intervals between photon detections using charging and discharging a capacitor with a constant current as well as a comparator. The time intervals can be in the range from 10 ns to 10 µs. With ±3.3 V supply voltage, the power consumption of the complete circuits is between 1.1 mW and 4.55 mW depending on the LED emission and detection rate of the SPAD. After XOR-hashing, the NIST tests were passed.