Patent ID: 7852162

Claim:
Noise source apparatus operative in conjunction with host apparatus generating, at intervals, a sampling clock which samples at least one output variable at a host sampling frequency, the apparatus comprising: a) a randomly activated deterministic pseudorandom number generating device operative to generate a first plurality of randomized binary streams; b) a frequency modulated oscillator operating at a second plurality of binary metastable frequency levels, at least some of which are uncorrelated to the sampling clock, the oscillator being operative to activate the pseudorandom number generating device; c) a frequency modulator circuit which is controlled by the pseudorandom number generating device and which generates oscillator input signals which define random intervals in the course of which the oscillator switches between its second plurality of binary frequency levels; and d) an encoding-sampling device receiving, encoding and sampling, in accordance with the sampling clock, the first plurality of randomized binary streams, thereby to generate at least one encoded sampled output, and feeding back an intermediate fed-back signal to the randomly activated deterministic pseudo-random number generating device.