Re: Looking for >5V pretty fast logic

On 22 Nov., 13:09, John Fields <jfie...@xxxxxxxxxxxxxxxxxxxxx> wrote:
On Thu, 22 Nov 2007 03:00:56 -0800 (PST), Klaus Kragelund





<klausk...@xxxxxxxxxxx> wrote:
Hi

I am using a CD4093 with 4 schmitt triggers wired as a free running
oscillator supplied by 10V. The CD4093 is 4000 series CMOS logic, but
it is just too slow for my application (need a 3MHz oscillator/VCO). I
can live with trigger level that has high tolerance and would shift
the frequency since the loop is closed to form a VCO

So been looking at the 74HC and other series, but cannot find anything
that can handle more than 6V and that is fast

Do any of you guys know of a chip? Or perhaps a faster VCO than the
CD4046 PLL. Alternatively building a astable oscillator with 2
MOSFETs. Maybe even a 74HC 5V IC, but with a simple levelshift to get
a fast 10V output

---
Why not use HC to get the speed you need and then a fast-ish
comparator to do the level conversion?

--
JF- Skjul tekst i anførselstegn -

- Vis tekst i anførselstegn -

Good suggestion. The problem is I need it to have low current
consumption and that is difficult to find when it needs to be fast
also (<100ns response)

Right now it looks like a LMC555 can do the trick

Thanks

Klaus
.

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