HA7210 Low Power Crystal Oscillator

[courtl]

Hi,

I have been using the HA7210 crystal oscillator for a number of years across a whole host of products. Its a simple IC with a crystal on the input giving a clock signal on the output. However I have received several batches lately made in different countries all of which have a failure rate of about 33% - where the O/P either works or it doesn't. I am struggling with the ones that fail to even get 400mV out. Has anyone else had similar problems?

Thanks
LC

 

[MacGyverS2000]

Has your installation or soldering method changed? Is it done by machines or by hand? Have you switched to Pb-free solder? Some things to look at...

Pb-free solder requires higher temps, which can cook components if you're not careful. Hand soldering can be a minefield, especially if it's one by someone wanting to finish up... they'll often times crank up the heat on the iron for a faster melt, same result as before. If done by IR oven, is the profile set correctly, and is the profile being followed?

Dan - Owner

http://www.Hi-TecDesigns.com

 

[courtl]

Hi,

Thanks for the suggestions but having found the failures initially within the products we have now tested the IC's directly out of packaging and they either work or they don't so it seems that the yield issue is from the manufacturer which is a little disappointing. This has also happened on different batches originating from different countries. We have also x-rayed the IC's and can see no obvious signs of why they are failing.

 

[itsmoked]

You need to get the local rep in and talk to him!

Keith Cress
kcress -

http://www.flaminsystems.com

 

[sreid]

Crystal oscillators are tricky beasts. You have to have enough gain to have a reasonably quick start up but not so much that you end up with a square wave output. The gain also has to drop off gracefully near the supply rails for the same reason. Also, the crystals have gain variations. The semiconductor process soes not have to be too far off for things to stop working.

I use the oscillator packages and let the manufacturer deal with these problems. And his probably work over the temperature range you need.