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laurijamsa
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Crystal problems

Hi,

We tried to use Epson TSX-3225 series crystal, but it didn't work. Load capacitance is 9pF - is that the only reason why it didn't work?

We need to select a good and cheap crystal which works -40C to +85C. Can you help with that? We changed the crystal to Abracon and seems that it started to oscillate.

http://www2.mouser.com/ProductDetail/Epson/TSX-3225-160000MF18X-AC3/?qs=...

http://www.abracon.com/Resonators/ABM8G.pdf

Device: 
MH_Dialog (not verified)
Hello Laruilamsa,

Hello Laruilamsa,

Epson TSX-3225 16MHZ, 10PPM, 9PF is also used on proximity or smart tag reference designs, so it should not cause any problems. 

Select a crystal with ESR lower than 100 Ohm. Higher ESR values will increase the 16 MHz Xtal oscillator start-up time. For crystals having 50 to 80 Ohm ESR values, start-up time is about 2 to 2.5 msec, for crystals having ESR of 100 Ohm or higher, it can be as long as 4 or 5 msec. Take this into account. Smaller sized 16 MHz crystal packages (e.g. size 2016) tend to have higher ESR values than larger cans (e.g. size 3225) have.

BR, MH_Dialog 

BB_Dialog
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Hello Laruilamsa,

Hello Laruilamsa,

I like to add something:

The TSX-3225 16MHz is a very fine 16 MHz crystal to be used with DA14580/581.

The C0 is not specified in the Epson PDF files, but we know it's less than 1.5pF. That's a nice value.
R values are about 50 Ohm, and Cload can be specified for a proper value (e.g 10 - 12 pF).
CL = 9pF should work fine as well.
All this leads to a fast start-up time.

Are your Xtal16M connections long? That could pick-up noise/interference and cause the oscillator to malfunction.
But that should also be the case when using the Abracon Xtal I.M.O.

Did you apply a trim-value for the 16MHz Xtal oscillator. If not, please try with a default trim-value of 1250 (decimal value).
This will result in about 10 pF Cload

Best regards, BB_Dialog.

laurijamsa
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Last seen: 4 years 1 month ago
Joined: 2015-03-12 11:25
Good to know that Epson TSX

Good to know that Epson TSX-3225 is good choice for the crystal. This problem was our bad, pinout was wrong :)

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