One of the simplest circuits for generating random analogue noise involves a reverse biased diode in either Zener or avalanche breakdown, and it is a variation on this that he’s using.

The Ninth Circuit had previously read the phrase “using a random or sequential number generator” as modifying only a system’s capacity to “produce” telephone numbers. [8] ...

Random generator: The digital circuits at the center of this electron micrograph image can emit a stream of random numbers at high speed. Such circuits could be integrated into future processors.

For FPGAs there are three circuits based on: a single XOR gate, a single LUT (look-up table), or a multiplexer with an inverter in the feedback loop. For asics, there is a four transistor circuit.

Random quantum circuit easiest way to beat classical computer Researchers suggest modeling chaotic circuits to demonstrate quantum supremacy.

[P]laintiff must allege facts permitting an inference that defendants called her with equipment that has the capacity to store or produce numbers using a random or sequential number generator.