I have made hundreds of custom teensy boards using a through hole Crystal with 2 load caps and they are all fine. I have now swapped to a smd crystal without the load caps and have had 2 out of 25 boards just die for no reason. The new boards are a totally new pcb layout but identical schematic to the previous through hole Crystal design.
I can only assume i have picked a wrong Crystal (16mhz,10pf) or my pcb layout is wrong? (no traces under Crystal, its right next to the mk20, has ground plane around / under it)
Cant think why these to boards worked great for two days then just died. They both still create 3.3v but apart from that there is no life.
My next step is to use the exact same Crystal the real teensy 3.2s use.
I can post schematics and board layout if needed.
Crystal used:
ABM8G-16.000MHZ-4Y-T3
http://www.mouser.com/ds/2/3/ABM8G-10572.pdf
Just noticed iv not connected the crystal GND (as the first crystal i selected did not require this, could this be the reason for micro dying?)
Here is top layer on pcb (nothing is on bottom layer under crystal apart from GND plane

Regards
Russell
I can only assume i have picked a wrong Crystal (16mhz,10pf) or my pcb layout is wrong? (no traces under Crystal, its right next to the mk20, has ground plane around / under it)
Cant think why these to boards worked great for two days then just died. They both still create 3.3v but apart from that there is no life.
My next step is to use the exact same Crystal the real teensy 3.2s use.
I can post schematics and board layout if needed.
Crystal used:
ABM8G-16.000MHZ-4Y-T3
http://www.mouser.com/ds/2/3/ABM8G-10572.pdf
Just noticed iv not connected the crystal GND (as the first crystal i selected did not require this, could this be the reason for micro dying?)
Here is top layer on pcb (nothing is on bottom layer under crystal apart from GND plane

Regards
Russell
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