Smallest Xtal

Do you have a question? Post it now! No Registration Necessary

Translate This Thread From English to

Threaded View
I am working on a design that needs to be as small as possible.  I
am using 0201 caps and resistors, and the smallest microcontroller
I can find.  So now the biggest component is the crystal.  What is
the smallest crystal package available?

I am not too picky about the freq, something in the range of 10 to
20 MHz.


Re: Smallest Xtal
Quoted text here. Click to load it

See this page:
http://www.golledge.co.uk/docs/products/xtl_sm/xtl_sm.htm

for a typical selection.

The smallest I see is 2.6 x 2.1 x 0.6 (all mm)

Cheers

PeteS


Re: Smallest Xtal
In comp.arch.embedded,
Quoted text here. Click to load it
Does it have to be a crystal? You may have better luck finding smaller
resonators and those also come with built-in caps. One example is the
Murata CSTCG_V series (20.00-33.86MHz), 2.0x1.3mm, built-in caps.

--
Stef    (remove caps, dashes and .invalid from e-mail address to reply by mail)

Often statistics are used as a drunken man uses lampposts -- for support
We've slightly trimmed the long signature. Click to see the full one.
Re: Smallest Xtal
stef33d@yahooI-N-V-A-L-I-D.com.invalid says...
Quoted text here. Click to load it
If your micro will accept a clock input, you might try a LTC1799
resistor-set oscillator.  It would require only the space of
an SOT23-5  and an  0603  resistor.

Mark Borgerson



Re: Smallest Xtal
On Fri, 16 Dec 2005 11:07:40 -0800, Mark Borgerson <mborgerson.at.comcast.net>

Quoted text here. Click to load it

Could you use a MCU with an on-chip RC oscillator. e.g. the newer PICs can be as
good as 1% - if you
need better could you calibrate agains some external signal ?  
I think Dallas/Maxim do some programmable oscillator chips that may be worth a
look if cost is not
too critical.

Another possibility is to use an LC oscillator - I think many MCU on-chip
oscillators can be used
with an LC combination instead of a crystal.

Re: Smallest Xtal
In comp.arch.embedded,
Quoted text here. Click to load it
Another thought: Some small micro's have built-in oscs, but these
are usually not very fast and not too accurate.

--
Stef    (remove caps, dashes and .invalid from e-mail address to reply by mail)

You may have heard that a dean is to faculty as a hydrant is to a dog.
We've slightly trimmed the long signature. Click to see the full one.
Re: Smallest Xtal

Quoted text here. Click to load it
There are some very small crystals available but do your sums and test them
carefully -  I've found that AVRs can be very reluctant to start with small
crystals. It's much smaller (and cheaper) to use the built in RC oscillator
if you can.  Silabs 8051 core parts and some AVRs these are pretty good.

MK

www.mkesc.co.uk




Re: Smallest Xtal
On Fri, 16 Dec 2005 16:23:12 -0000, the renowned "MK"

Quoted text here. Click to load it

The smallest SMT crystals typically have rather low maximum power
dissipations, often <= 100uW, compared to the several mW that you can
safely pump into a HC49 can without damaging it. That means the
oscillator design is more fussy to get a circuit that will reliably
start over the temperature range without damaging it. Yeah, it's
usually just one extra resistor on the typical Pierce on-chip
oscillator, but...  


Best regards,
Spehro Pefhany
--
"it's the network..."                          "The Journey is the reward"
snipped-for-privacy@interlog.com             Info for manufacturers: http://www.trexon.com
We've slightly trimmed the long signature. Click to see the full one.
Re: Smallest Xtal
Quoted text here. Click to load it

Do you need the Xtal ? No crystal is the smallest :)
Quite a number of uC now have on chip OSC, that are calibrated,
and in the 10-30MHz region.
Actel's fusion specs 100MHz with 1% precision on chip osc.
(No curves published yet, but if true, and indication of the leading
edge....)
-jg


Re: Smallest Xtal
Bob wrote On 12/16/05 03:05,:
Quoted text here. Click to load it

Surface mount. It does not get any smaller.


Re: Smallest Xtal
Quoted text here. Click to load it

If exact frequency is not needed, either use a MCU with internal
RC-oscillator (as suggested) or use an SMD inductor instead of the XTAL,
most chips work fine with that.
Frequency is 1 / (2 * pi * squareroot(L * C)) with C being the series
replacement of the external caps (half the C's value if both are equal).

---
Arie de Muijnck



Re: Smallest Xtal

Quoted text here. Click to load it

Depending on the shape of the available space, maybe you could use  aw atch
crystal type package
sitting on top of other parts.

Re: Smallest Xtal

Quoted text here. Click to load it

Use one of the new generation silicon clock generators. They are
available in very small packages. Some can be programmed over a
1 wire bus to the frequency you need. Others use one external resistor
to set the frequency. Maxim, Linear Technology and others manufacture
these devices.

Regards
  Anton Erasmus

Re: Smallest Xtal

Quoted text here. Click to load it

If you get hold of a old/bad computer motherboard, there is likely a very
small 14.something MHz crsytal on there.

Mat Nieuwenhoven



Re: Smallest Xtal

Quoted text here. Click to load it

Likewise, old NTSC video gear.



Site Timeline