Hi all,
I like to use crystals vs resonators for AVR boards (both Arduino and home made standalone). To replace the resonator on an Arduino board, a 2 smd no-lead package of size 3.2mm x 2.5mm in needed. I unsolder the resonator, remove the center PCB trace (gnd) with a razor blade and hot air solder on the crystal. Of course I would like to use the same type of crystal for standalone boards as well (the package neatly fits between adjacent pads of a protoboard).
My problem / question is this: the only value crystal I can get in the 2 smd 3.2x2.5 package is 16.0000 MHz. I prefer to use 22.1184 MHz. crystals to get "integer perfect" serial baud rates.
Unfortunately, the only package that this frequency is available in (in the 3.2x2.5 size) is 4 smd. The 4 smd parts have 4 pads on the bottom, a diagonal pair are the crystal and the other diagonal pair are case ground.
Obviously, soldering these to an Arduino board will produce a direct short across the MCU crystal pins.
My idea is to either solder a small piece of wire to each ground pad and use it to rip the pads off the package, or else use a razor blade to get under the pads and peel them off the package (or if the ground pads ONLY contact the case from the outside, cut the connection between the pads and the case with a razor blade).
I know this seems barbaric, but I don't see any other way to do it.
So, the questions:
* Will the crystal work OK without the case grounded?
* Should I solder a tiny wire from the case to ground to re-establish the ground?
* Will removing the pads the way I described destroy the crystal?
* Anyone have a better idea?
Any input will be appreciatted.