CD4060 Xtl Osc. Circuit
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From: Phil Hobbs on 17 Mar 2010 08:14 On 3/17/2010 6:10 AM, JosephKK wrote: > On Fri, 12 Mar 2010 20:55:06 -0500, Phil Hobbs<pcdhSpamMeSenseless(a)electrooptical.net> wrote: > >> On 3/12/2010 7:45 PM, Joerg wrote: >>> Steve Upton wrote: >>>> I have copied the CD4060 part of the CMOS synthesizer in the link >>>> below to the letter, but it does not work. I am using a 12VDC SLA for >>>> supply. It tries to start when I tease the caps, but then dies. >>>> >>>> I've spent hours tinkering to no avail. Can anyone see what is might >>>> be going amiss? ... >>> >>> >>> Not knowing which frequency you are using, the 100k is way too low. I >>> never go below 1M. Also, the burden caps are highish, 100pF is a bit much. >>> >>> >>>> ... Or can anyone please provide a similar circuit that works? >>>> >>> >>> Yup: >>> >>> http://www.edn.com/contents/images/6553623.pdf >>> >>> >>>> http://www.redclifferadioclub.org.au/QRM/2006%2010%20-%20October%20QRM.pdf >>>> >>>> >>> >>> How on earth could you guys call your club bulletin "QRM"? ... :-) >>> >>> (for non-hams: QRM means noise, of the undesired kind, meaning not from >>> a rock band and stuff) >>> >> Nah, noise is QR*N*. QRM is interference, usually other random lusers >> gassing about their equipment. >> >> Cheers >> >> Phil Hobbs > > Please recheck Phil, i remember QRN as being QRNovice (pejorative). Quit giving me static. ;) http://en.wikipedia.org/wiki/Q_code Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal ElectroOptical Innovations 55 Orchard Rd Briarcliff Manor NY 10510 845-480-2058 hobbs at electrooptical dot net http://electrooptical.net
From: Jim Thompson on 17 Mar 2010 11:16 On Wed, 17 Mar 2010 03:36:03 -0700, "JosephKK"<quiettechblue(a)yahoo.com> wrote: >On Sun, 14 Mar 2010 14:29:37 -0700, Jim Thompson <To-Email-Use-The-Envelope-Icon(a)My-Web-Site.com> wrote: > >>On Sun, 14 Mar 2010 13:34:49 -0700, Joerg <invalid(a)invalid.invalid> >>wrote: >> >>>Jim Thompson wrote: >>>> On Sun, 14 Mar 2010 13:25:18 -0700, Joerg <invalid(a)invalid.invalid> >>>> wrote: >>>> >>>>> Jim Thompson wrote: >>>>>> On Sun, 14 Mar 2010 09:51:52 -0700, Joerg <invalid(a)invalid.invalid> >>>>>> wrote: >>>>>> >>>>>>> Jim Thompson wrote: >>>>>>>> On Sun, 14 Mar 2010 09:05:27 -0700, Joerg <invalid(a)invalid.invalid> >>>>>>>> wrote: >>>>>>>> >>>>>>>>> Jim Thompson wrote: >>>>>>> [...] >>>>>>> >>>>>>>>>> My rule of thumb, which seems to work with every inverter-style >>>>>>>>>> crystal oscillator I've ever tried: Use capacitors as recommended by >>>>>>>>>> the crystal specification... if it says 15pF, that means 30pF on EACH >>>>>>>>>> end to ground. Then choose the resistor based on 45� phase shift with >>>>>>>>>> the first capacitor (at the crystal frequency). >>>>>>>>>> >>>>>>>>> I am usually happy with around 1M. All it needs to do is to crank it >>>>>>>>> over. Kaaaa-chum-pah ... POOF ... vrooooom. Unless I must start it >>>>>>>>> really fast for some reason but that can require special kicker circuitry. >>>>>>>> Huh? You and I are talking two different resistors. I'm talking the >>>>>>>> series drive resistor; you're talking the DC loop resistor. >>>>>>>> >>>>>>> Ok, different thing. Mostly you can get away without although that's not >>>>>>> always the nice way of doing things. >>>>>>> >>>>>>> >>>>>>>> Which brings to mind... does the CD4060 have the DC loop resistor >>>>>>>> built-in? It would appear not. >>>>>>>> >>>>>>> AFAIR not. >>>>>>> >>>>>>> >>>>>>>> And I should pay closer attention to details :-( The OP has 100K >>>>>>>> there... needs to be 10-20Meg. >>>>>>>> >>>>>>> I usually go for 1M. >>>>>> CD series stuff doesn't have a lot of gm. But 1Meg is good for >>>>>> something like 74HCU04. >>>>>> >>>>> For the CD4060 they recommend even higher values, page 3: >>>>> >>>>> http://www.fairchildsemi.com/ds/CD%2FCD4060BC.pdf >>>> >>>> Didn't I say 10-20Meg ?:-) >>>>> >>>>>> DO NOT USE buffered inverters for crystal oscillators! >>>>>> >>>>> Depends on the frequency but generally yes, don't use those if you can >>>>> avoid it. >>>> >>>> Makes for lousy stability and possible non-starts. >>>> >>> >>>I never had those problems. But I also prefer non-buffered inverters for >>>that. >>> >>>>> >>>>>>> 10M may not work outdoors when humidity is high and >>>>>>> some condensation occurs. >>>>>> Mine are usually on-chip :-) >>>>>> >>>>> Yup, a poly resistor is nice. But you can't put crystals on the chip :-) >>>> >>>> Wanna bet ?:-) >>>> >>> >>>With MEMS you could, lots of things are possible. But unlikely as good >>>as a real crystal. >> >>You _can_ mount a membrane type crystal onto a chip, though, right >>now, we're mounting the crystal separately... hybrid board style. >> >> ...Jim Thompson > >Excuse my ignorance, but that sounds very scary. Physical mode control >would have to be very reliable; else there could be unwanted transferred >mechanical stresses. Membrane!! "Thick" ring with etched membrane (from both below and above). ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | The only thing bipartisan in this country is hypocrisy
From: Joerg on 17 Mar 2010 11:20 JosephKK wrote: > On Sun, 14 Mar 2010 16:10:43 -0500, Vladimir Vassilevsky <nospam(a)nowhere.com> wrote: > >> >> Joerg wrote: >> >>> Vladimir Vassilevsky wrote: >>> >>>> >>>> Joerg wrote: >>>> >>>>> Yup, a poly resistor is nice. But you can't put crystals on the chip :-) >>>> >>>> Isn't it what Maxim does in their clock ICs ? >>>> >>> I never use Maxim parts. If you mean the former Dallas series 32kHz >>> things those are modules that contain a tuning fork crystal. They may >>> look like a chip but in reality it's modules. And my clients would >>> probably have my head examined if I placed a timing clock oscillator >>> that costs several Dollars :-) >> There are not too many choices when you need an RTC. Besides, some >> Dallas/Maxim parts offer the ability to adjust the clock frequency >> digitally, so you can phase lock it to external signal. That's not too >> bad for few dollars. >> >> VLV > > May i suggest that both of you reacquaint yourselves with NTP (network > time protocol). It is an intentionally very simple protocol, with > intentionally very useful byproducts. Can be a challenge. For example some of my stuff gets deployed way out there. Sometimes there isn't even cell coverage, let alone an Internet connection. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Vladimir Vassilevsky on 17 Mar 2010 11:41
JosephKK wrote: > On Sun, 14 Mar 2010 16:10:43 -0500, Vladimir Vassilevsky <nospam(a)nowhere.com> wrote: > > >> >>Joerg wrote: >> >> >>>Vladimir Vassilevsky wrote: >>> >>> >>>> >>>>Joerg wrote: >>>> >>>> >>>>>Yup, a poly resistor is nice. But you can't put crystals on the chip :-) >>>> >>>> >>>>Isn't it what Maxim does in their clock ICs ? >>>> >>> >>>I never use Maxim parts. If you mean the former Dallas series 32kHz >>>things those are modules that contain a tuning fork crystal. They may >>>look like a chip but in reality it's modules. And my clients would >>>probably have my head examined if I placed a timing clock oscillator >>>that costs several Dollars :-) >> >>There are not too many choices when you need an RTC. Besides, some >>Dallas/Maxim parts offer the ability to adjust the clock frequency >>digitally, so you can phase lock it to external signal. That's not too >>bad for few dollars. >> >>VLV > > > May i suggest that both of you reacquaint yourselves with NTP (network > time protocol). It is an intentionally very simple protocol, with > intentionally very useful byproducts. I am aware of NTP and IEEE 1588. It requires master clock station regardless; the accuracy is insufficient for our applications. VLV |