[sdiy] MFOS Seq ext clk in

[Samppa Tolvanen]

On Fri, Jun 5, 2009 at 1:04 PM, Tom Adam<tom.adam at thebigear.be> wrote:

> I was checking some signals and I found that I need a rather large 10Vpp
> signal to get the external clk in to work. I don't remember if it was a
> 0-10V or -5 to 5V signal, but I can check that again.

CD40106 Schmitt Trigger has +12 Vcc, so it probably needs a hefty ~10V
signal to change state. Just use an amp, because you want to retain
Schmitt Trigger characteristics to drive it reliably from sine waves.
(It should square that off with enough precision for clocking
purposes)

Samppa