M
Michael
- Jan 1, 1970
- 0
I need to replace a 3.6 MHz VCO which drives a uC. Looking at xtals, TCO's and
OCXO's in DigiKey, you'd think that nobody ever used - or has use for - a 3.6
MHz clock. There's some high speed, crazy freq. stuff but no 3.6 MHz.
OK, I'll bag accurate and stable and settle for a vanilla osc. Can't find a 3.6
MHz. Try a multiple of 3.6 How about 7.2 (3.6 x 2)? No got, but there is
7.3728. Or 10.8 (3.6 x 3) or 18.0 (3.6 x 5)? (Odd multiples suck but I'm
getting desperate.)? Plenty of 10.24. But I DO find 18.0 and - wonder of
wonders! - 36.0! (3.6 x 10)
I'll get a 36 MHz and run the output thru a decade counter. Lessee ... vanilla
74 family can't hack it. We'll go with 74HC. (sound of shuffling pages here)
Here 'tis, but only basic functions - OR, AND, etc - and some others ... except
counters. What happened to all the 74HC stuff over the past 10 years or so,
while I wasn't looking?!
OCXO's in DigiKey, you'd think that nobody ever used - or has use for - a 3.6
MHz clock. There's some high speed, crazy freq. stuff but no 3.6 MHz.
OK, I'll bag accurate and stable and settle for a vanilla osc. Can't find a 3.6
MHz. Try a multiple of 3.6 How about 7.2 (3.6 x 2)? No got, but there is
7.3728. Or 10.8 (3.6 x 3) or 18.0 (3.6 x 5)? (Odd multiples suck but I'm
getting desperate.)? Plenty of 10.24. But I DO find 18.0 and - wonder of
wonders! - 36.0! (3.6 x 10)
I'll get a 36 MHz and run the output thru a decade counter. Lessee ... vanilla
74 family can't hack it. We'll go with 74HC. (sound of shuffling pages here)
Here 'tis, but only basic functions - OR, AND, etc - and some others ... except
counters. What happened to all the 74HC stuff over the past 10 years or so,
while I wasn't looking?!