I need a circuit that generates rectangular waves. It shouldn't be lo-hi-lo-hi, but a random sequence of lo-hi-hi-hi-lo-lo is needed. It also has to oscillate like that, at at least 20MHz. I don't mind getting a special IC... Anything to make the job easier is fine by me.
Alright, I'm looking for really dead-easy ones and so thanks Nick for the solution. I'm also considering something possibly even smaller.
Please bare with me.
Maybe I can use an ordinary digital oscillator and then dynamically change its oscillating frequency (change in frequency also in terms of MHz), so that the level signals get dilated and compressed, giving the effect that we have randomly generated bitstreams. Though we have to set the targeted frequency (in this case, 20MHz), as the lower limit of changing the frequencies.
Something like this, an LTC6905 - http://cds.linear.com/docs/en/datasheet/6905fd.pdf (ok, not exactly cheap), and then vary the setting resistor in small increments/decrements randomly.
Of course there is a problem of randomly changing the resistance that is itself at least pseudo random. So it's back to square one. Any comments on this??