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CMOS oscillator said to beat quartz

10/22/2010 06:11 PM EDT
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daleste
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re: CMOS oscillator said to beat quartz
daleste   10/22/2010 6:29:52 PM
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Very nice solution. I guess with the noise problems, it will never be integrated onto the ASIC. Can it be used in a separate package in the system or does it have to be packaged with the ASIC to avoid stray capacitance and ground loop issues?

RebounD11
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re: CMOS oscillator said to beat quartz
RebounD11   10/22/2010 9:06:40 PM
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noise problem? The phase noise seems a little lower than in other types of CMOS oscillators and should be much lower at the frequencies at which it is user configurable. I'm also pretty sure it will have an option of being separately packaged, since wire bonding is also used for linking silicon to the package. That's my 2 cents anyway.

old account Frank Eory
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re: CMOS oscillator said to beat quartz
old account Frank Eory   10/22/2010 9:31:45 PM
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Lots of people have integrated high frequency LC oscillators on CMOS SoCs, so in reality the noise problems are not such an insurmountable barrier to integration. But IDT is not in the SoC business and is not offering this as an IP block for others to integrate -- hence, the discussion in the article about IDT selling bare die so you can do stacked die in one package. Either way, you achieve ths same result -- eliminating the quartz crystal -- which is the whole point. IDT has taken this nicely compensated LC oscillator plus dividers and built it as a stand-alone chip that targets quartz oscillator replacement for clock frequencies up to 133 MHz -- a clever marketing approach that could be very successful for them. I do think, however, that the article title is somewhat misleading. "beat quartz" are not the words I would use to describe an oscillator that is "almost as accurate as quartz."

R_Colin_Johnson
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re: CMOS oscillator said to beat quartz
R_Colin_Johnson   10/22/2010 10:03:12 PM
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Here CMOS offers comparable performance, but "beats" quartz in size and price. Unfortunately a headline is too short to explain what it means--that's what the story is for :)

R_Colin_Johnson
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re: CMOS oscillator said to beat quartz
R_Colin_Johnson   10/22/2010 8:30:09 PM
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Yes, it can be packaged on its own too. In fact, I believe you can set up its pinout to match that of the quartz oscillator it is replacing.

sharps_eng
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re: CMOS oscillator said to beat quartz
sharps_eng   10/23/2010 7:56:01 AM
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I like the 100us start-up time. Crystals can be 500 times slower - not every newbie remembers that in their uP reset circuit design.

Timing Guy
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re: CMOS oscillator said to beat quartz
Timing Guy   10/23/2010 4:09:31 PM
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I'm concerned about the costs. They get to 100ppm by testing and throwing away the parts that are out of spec. Gets way too expensive. Quartz will be king forever!!!

old account Frank Eory
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re: CMOS oscillator said to beat quartz
old account Frank Eory   10/23/2010 4:16:37 PM
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Forever is a long time Timing Guy. Not too many years ago it was a given that a good radio receiver required a SAW filter. But since the SAW couldn't be integrated in silicon, clever engineers found a way to design it out in many applications. Never say never...

Silicon Guy
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re: CMOS oscillator said to beat quartz
Silicon Guy   10/23/2010 8:54:55 PM
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This is a rather odd comment from Timing Guy. First, I've seen one of IDT's talks and they use a massively parallel test to trim every single device so yield should be in the high nineties in terms of percentage. They certainly don't "throw" anything away other than typical semiconductor yield loss due to defect density which should be very small with such a small die. Second, and assuming I am understanding correctly, by offering the die product, they are selling directly against passive resonators. That ASP is probably around $0.10 or less. Interestingly, that suggests that the CMOS oscillator is much lower cost than commoditized quartz. It seems like a real threat to quartz to finally make the function in standard silicon.

agk
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agk   10/31/2010 6:53:00 AM
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Yes to the words of silicon guy and Frank. CMOS oscillator soon going to replace the crystal oscillators with many advantages like cost,accuracy and integarability,quick start up time,low jitter etc.

krisi
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re: CMOS oscillator said to beat quartz
krisi   10/23/2010 5:30:39 PM
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Interesting development, for those who would like to hear IDT presentation they will presenting at CMOS Emerging Technologies workshop in Whistler in 2011, details at www.cmoset.com Kris

Sheetal.Pandey
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re: CMOS oscillator said to beat quartz
Sheetal.Pandey   10/24/2010 3:19:02 AM
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Thanks Kris. I will visit that site. This is a veyr interesting development indeed. It will be a relief to many board designers, no extra routing if its going to sit on ASIC. But I would love to know if the performance remains same as in conventional designs.

yalanand
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re: CMOS oscillator said to beat quartz
yalanand   10/24/2010 5:25:53 PM
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Wow, this is really cool. So we will not see those bulky oscillators when we open our digital watches :). Overall the spec is pretty gud and is comparable to the conventional oscillators available in the market.

bfemmel
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re: CMOS oscillator said to beat quartz
bfemmel   10/25/2010 9:31:30 PM
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I don't think this will be in your new watch anytime soon as it still is in the 2mA range. Quartz oscillators for your watch will be under 1uA.

Sanjib.A
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re: CMOS oscillator said to beat quartz
Sanjib.A   10/24/2010 5:51:46 PM
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Having 100ppm accuracy and less than 457 femtosecond phase jitter along with greater immunity to stray electrical fields and protection against changes in the environment, such as humidity, the IDT3C02 looks to be the best CMOS based oscillator available, isn't it?

krisi
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re: CMOS oscillator said to beat quartz
krisi   10/25/2010 6:01:18 PM
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Can anyone explain how this technology works? Any grad student can build LC oscillator that oscillates at hundres of MHz or few GHz (I know first hand, I had a few students who built that)...by neither L or C are predictable so you will get a value of oscillation frequency which will be 20% off or so...you can tune that in with C (using varactor) or less likely with L (using some switches to connect more L if needed)...but how do you maintain that tuning over life of the product, temp changes, VVD variations etc...any hint is appreciated...Kris

jg_
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re: CMOS oscillator said to beat quartz
jg_   10/25/2010 9:45:21 PM
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I see IDT claim 73c/10K, which is ok, but not much below even Digikey Crystal Osc prices. There are also 1mA Crystal Oscillators, so their claims of lower power is more 'average', rather than comparing leading edge, with leading edge. I can see it has a place, replacing the very bottom spec'd crystals, but Ceramic resonators are more threatened here. The wide supply range is impressive. Missing from their data sheet, is the Base Freq, I see mentioned above as 3GHz. Also missing is any breakout of the 100ppm components : no dF/dT, dF/dV, etc

dnh
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dnh   10/26/2010 1:49:49 AM
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The title is missleading. 100ppm is nowhere close to even good crystal oscillators, let alone the best. Besides, 100ppm is meaningless without a temperature range. DHorn

Sanjib.A
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re: CMOS oscillator said to beat quartz
Sanjib.A   10/28/2010 2:14:47 PM
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I agree with you. The title could be over-optimistic for the IDT3C02 CMOS oscillator. But this "all-silicon" oscillator could certainly beat the 100 ppm quartz crystal oscillators available in the market...isn't it?

martinm_de
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re: CMOS oscillator said to beat quartz
martinm_de   10/26/2010 7:20:39 AM
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The length change of silicon is 2ppm/Kelvin Length change of Aluminium is 23ppm/K Copper has 16ppm/K Lets assume that the silicon length change overrides the length change of the metal (whatever is used) , a temperature change of 50 Kelvin causes an inductance change of 100ppm Same for the capacitors, I guess. I have no idea how they trim the circuit to compensate the +/-20% process spread of the capacitors. Laser trimming? I see no space for a fractional PLL.

Code Monkey
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re: CMOS oscillator said to beat quartz
Code Monkey   10/29/2010 7:18:34 PM
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I'm sure OTP fuses or something compensate for process spread. ATE would measure the 3GHz and program the divider accordingly.

gautham
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re: CMOS oscillator said to beat quartz
gautham   10/30/2010 4:40:09 PM
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Yes, I've been following these guys since they published their work at the ISSCC 2007: http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=4077168 when they were still Mobius Microsystems. If I remember correct, the paper mentions using an elaborate digital calibration with the aid of an external reference clock to achieve sub-100ppm setting accuracy.

M5NOMAD12
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re: CMOS oscillator said to beat quartz
M5NOMAD12   11/2/2010 11:36:20 PM
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Aging? What about the Aging? Will they spec 1 year and add that in the 100 PPM spec? What does it do 3 to 5 years down the road. Short Term Stability? 457 femtosecond phase jitter. Yes but defined over what range? The range where the LC oscillator is optimum? Achieves -140dBc/Hz phase noise; yes but at what offset frequency? Yes but I have 1 more question to ask; if this is such a great technology then what happened to Mobius Microsystems? Why was it acquired by IDT earlier this year.

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