Sure here's something very simple take [0].
This is for RF, and you probably need less bandwidth. Search on Robert Penfold hobby designs for noise generators for audio too. In practice you'll need to do a few things to get a good digital noise source with proper entropy.
1) Shield it! What you want is noise from the bandgap transition not from your local radio station or ambient "cosmic" noise.
2) Thermally stabilise it.
3) Convert to a digital stream. A Schmitt gate with properly set hysteresis to get clean edge transitions and a 1-bit sampling circuit.
The whole design should cost you a few bucks and be buildable in hours. Maybe use a USB audio dongle (minus the DC block capacitors) as an easy-in for your digital side.