App note: Selecting and testing 32kHz crystal oscillators
Atmel describes how to select and test 32.768 kHz quartz crystals [PDF!] for real-time clocks. The basic tips on layout apply to any microcontroller project, not just those with AVRs.
This entry was posted in app notes and tagged 32.768 KHz, app note, atmel.This application note summarizes the crystal basics, PCB layout considerations, and how to test a crystal in your application. A crystal selection guide shows recommended crystals tested by experts and found suitable for various oscillator modules in different Atmel AVR families. Test firmware and test reports from various crystal vendors are included.
Comments
super cool sockets … want some :)
as for usability of the texts for “general purpose mcu’s”, most mcu’s I used don’t have internal load so you require external capacitors and this then requires some special pcb design .. having internal load is nice feature, unfortunately not that common
Interesting PDF.
SOIC can be bent and reversed once however TQFP are very prone to break off and that’s really bad.
Also these pierce oscillators are pretty much makebelieve, they won’t operate some crystals in the correct mode (there is parallel and series resonance), so there must be additional components to correct the shift. Even some older MCUs actually don’t use pierce oscillator.
I have soldered SMD chips using magnet wire (some years agp), but over time it was so bad I have taken apart all these prototypes, and have transfered the chips on adapter PCBs.
I was going to ask where the pic came from – until I opened the PDF :-D. . . Pretty funny to see deadbug rework visually documented in an app-note – although it certainly does make sense here.
Me too