[time-nuts] Linear Interpolator

Brooke Clarke brooke at pacific.net
Fri Jun 30 19:30:05 EDT 2006

Hi Brooks:

I too got the quote on the GP2 and checked the ExpressPCB software 
package that does both schematic capture and board layout and it has a 
template for the QFN32 package.  For comparison I placed the ICS525 
template right beside the QFN32.  The ICS525 has 1/4 pitch (0.025") but 
the QFN is 0.5 mm (0.02") which is a little finer.

I have been able to mount the ICS525 using either solder paste or just 
an iron.  For more on working with SMT parts see my web page:

I agree with Randy's comment that the pad on the board needs to be 
longer to give an iron a place to work.  Also solder mask sure is a big 
help, and that's why it exists.

If there's a desired circuit I'm fairly sure I could build it.

Have Fun,

Brooke Clarke

w/Java http://www.PRC68.com
w/o Java http://www.pacificsites.com/~brooke/PRC68COM.shtml

Brooks Shera wrote:

>Inspired by Ulrich's lead regarding the high resolution TDC, I asked the 
>Acam US rep for a quote on the TDC GP2. As Ulrich indicated they are not too 
>expensive:  $28 quantity 1, $26 quantity 10. Sounds great.   Temperature 
>coefficient isn't quoted but it will be considerable - presumably can be 
>corrected in software.
>For me the catch seems to be that they are packaged in a QFN-32.   The pin 
>spacing is 500 microns and the open space between the solder pads is only 
>200 microns.  Perhaps I am too timid but this sounds like trouble for manual 
>soldering, that's assuming the low cost PCB suppliers could make the 
>appropriate solder mask.  Any comments from the experienced?
>Acam makes a dandy evaluation board, the ATMD-GPX, but for this they want 
>$2298.   Oh well.
>----- Original Message ----- 
>From: "Ulrich Bangert" <df6jb at ulrich-bangert.de>
>To: "'Discussion of precise time and frequency measurement'" 
><time-nuts at febo.com>; "'Magnus Danielson'" <cfmd at bredband.net>
>Sent: Thursday, June 29, 2006 11:41
>Subject: Re: [time-nuts] Linear Interpolator
>Hi Stephan,
>if you need a ps resolution time interval counter for use in a project
>of your own, why not simply go out and buy you one? For example here
>They are not that expensive because they are made to be married with
>cheap sensors.
>time-nuts mailing list
>time-nuts at febo.com

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