I'd like to build a true random number generator. The gold standard appears to be using quantum phenomenon.
One approach (thank you Wikipedia.org) is:
As I plan to hook up the microcontroller via USB and have an existing board in mind, there are some design considerations/constraints:
- Vcc is 5V (3.3v is available also, but with only about 20mA available)
- no more than 100mA (though ideally a lot less)
- low component count and SMD devices (quicker and easier to make!)
- shielding? Noise immunity (other than quantum tunneling noise) is essential!
One approach (thank you Wikipedia.org) is:
Amplification of the signal produced on the base of a reverse-biased transistor. The emitter is saturated with electrons and occasionally they will tunnel through the band gap and exit via the base. This signal is then amplified through a few more transistors and the result fed into a Schmitt trigger.
This is the approach I would like to take. I understand the basic working principle, but have no idea where to start designing the circuit. I have experience with microcontrollers, so if I can amplify the signal to a 0-5v range, I can use an ADC to turn it into digital information.
As I plan to hook up the microcontroller via USB and have an existing board in mind, there are some design considerations/constraints:
- Vcc is 5V (3.3v is available also, but with only about 20mA available)
- no more than 100mA (though ideally a lot less)
- low component count and SMD devices (quicker and easier to make!)
- shielding? Noise immunity (other than quantum tunneling noise) is essential!