Searching \ for '[PIC]: Surface Mount Crystals' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/microchip/devices.htm?key=pic
Search entire site for: 'Surface Mount Crystals'.

Exact match. Not showing close matches.
PICList Thread
'[PIC]: Surface Mount Crystals'
2002\06\11@101328 by Lawrence Lile

flavicon
face
I've been trying to specify some surface mount crystals.  I have two on my
board, one a 4MHz and one 32.768 khz.

Now, the thru-hole 4 MHz crystals come in a pretty big can, the standard
HC-49U package.  The thru-hole 32 kHZ cryustal comes in a tiny little can
looking about half the size of a 1 uF Cap.

In surface mount, I have only been able to locate crystals in gargantuan
packages that look like HC-49's with saurface mount tabs on the bottom.  The
surface mount 32 khz crystal is actually *bigger* than the thru hole 32khz
crystal, by about 10X.  I am not used to buying surface mount parts that are
*bigger*  than thru-hole.   Kinda like a subcompact car longer than a
Caddilac.

What type of crystals do you folks use on surface mount projects, and how
small do they get?

--Lawrence



{Original Message removed}

2002\06\11@102807 by Peter Betts

picon face
> What type of crystals do you folks use on surface mount
> projects, and how small do they get?

I use HC49/4HSMX style packages for my 20MHz Xtals. They are like normal HC49/U packages but about 4mm high
In fact they are HC49/H packages but with surface mount pads rather than legs.

HC49/4HSMX  are 10.8*4.9*4.3mm (Length, Width,Height)

Pete

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\06\11@105857 by Rick C.

flavicon
face
You're right, the smt versions are a bit larger. The smallest ones I've seen are
the same footprint as the t/h versions--they just have a tab at each end or the
leads are folded over and held in place with a plastic spacer. I'm helping to
close down a major auto manufacturer instrument cluster line, and they have a 4
mhz xtal in a flat pack but the footprint is actually larger than the t/h
version. Go figure. Whatever you specify, just make sure you can second source
them. Digikey has what looks like a small one p/n XC587CT-ND $1.95 single qty.
that looks good. http://ecsxtal.com/pdf2/CSM-12.PDF
Rick

Lawrence Lile wrote:

{Quote hidden}

> {Original Message removed}

2002\06\11@110313 by Alan B. Pearce

face picon face
>Now, the thru-hole 4 MHz crystals come in a pretty big can, the standard
>HC-49U package.  The thru-hole 32 kHZ cryustal comes in a tiny little can
>looking about half the size of a 1 uF Cap.

I'm using a 3.6688MHz HC49/3U can that is about a 1/4 the height of a full
HC49/U can. Mine came from CMAC.

This is then about a suitable size for having on a surface mount board
unless your packing the boards real tight against each other.

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\06\11@111336 by Peter Betts

picon face

> I'm using a 3.6688MHz HC49/3U can that is about a 1/4 the
> height of a full
> HC49/U can. Mine came from CMAC.

I get mine from Farnell.


> This is then about a suitable size for having on a surface mount board
> unless your packing the boards real tight against each other.

I pack my boards apart with 4mm spacers/connectors. Tight fit as the Xtals are 4.3mm but generally the connectors give a little. No problems so far. In fact all my circuits are SMT now (PCBs made by Tsvetan Usunov at Olimex which I must highly recommend for a fast and efficient results)

The connectors are also available from Farnell
http://www.farnell.com

regards
Pete

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\06\11@112834 by Alan B. Pearce

face picon face
>> I'm using a 3.6688MHz HC49/3U can that is about a 1/4 the
>> height of a full
>> HC49/U can. Mine came from CMAC.

>I get mine from Farnell.

Well to be pedantic mine come from RS, but are made by CMAC :)

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\06\11@174309 by Peter L. Peres

picon face
On Tue, 11 Jun 2002, Lawrence Lile wrote:

>
>What type of crystals do you folks use on surface mount projects, and how
>small do they get?

The plastic lying down kind (SMD-ized normal small cylindrical 32kHz
crystal - has a PCB shell and four pads one at each corner). It is large.
I have glued normal bare metal crystals on top of chips before, to save
area.

Peter

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


More... (looser matching)
- Last day of these posts
- In 2002 , 2003 only
- Today
- New search...