In a random number generator, a first converter converts a first analog noise signal into a random digital clock signal and a second converter samples a second analog noise signal asynchronous to the first analog noise signal in response to the random digital clock signal and generates a random digital number stream. In one aspect, a random number generator output block samples the second converter random digital number stream in response to the random digital clock signal and generates a random number generator block output. In another aspect a pseudo noise source state machine generates the random digital clock signal in response to a first seed generated from the first analog noise signal, a second seed from process variation digital amplifier, and a past machine state.