with
load
sheet;
counted in
xtals...
I knew you did! =) And I agree that it's small figure in the mentioned case - however for low load xtals I figure it might be siginifcant. For sure it is with the MSP430 that can load 6pF watch crystals...
is
more
GPs? (If its bad I'll throw the first 0201 cap at him ;-)
Cheers, Anders
That sounds resonable. Maybe I should consider them. At least they MUST be smaller than my current HCU49 xtals... Any other dirt one should consider? Are they available in UART friendly frequencies around 4MHz? Problems with startup? Other?
Cheers, Anders
Freeze spray is your friend, along with a heat gun. Messing with the micro power supply can be useful too - Vmin to Vmax. A few years ago we had a whole bunch of Rabbit RCM2200 ethernet modules that killed their crystals by overdriving them - worked fine for a few months, then crystals failed completely (its very hard to run ethernet without a clock). I spent a few hours trying to kick-start them (many different c's, T etc) to no avail. An analysis of the circuit soon showed the crystal drive levels were very high, and although a series R was present the manufacturer used an 0R0 link. 1k was a *MUCH* better choice (IIRC). I talked to Rabbit, and they acknowledged the design fault, since rectified (I wasnt the only customer to find this).
To be fair it can be quite tricky to work out what drive level the crystal can take, as manufacturers can be loath to part with this info.
Cheers Terry
Have something to add? Share your thoughts — no account required.
Ask the community — no account required