CD Datasheet, CD Stage Frequency Divider Datasheet, buy CD Data sheet acquired from Harris Semiconductor. SCHS Page 2. Page 3. Page 4. Page 5. Page 6. Page 7. Page 8. IMPORTANT NOTICE. Texas Instruments. all relevant TOSHIBA information, including without limitation, this document, the specifications, the data sheets and application notes.
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Home Questions Tags Users Unanswered. To participate you need to register. It’s gotta be one of the simplest programs you can do. Note that the TI datasheet is a scan of an earlier Harris Semiconductor ratasheet, so it does not have the high resolution of typical modern datasheets. I wasn’t born datwsheet CD-series logic in hand so maybe I’m missing datashset something obvious Maybe they did not update their datasheet.
I was thinking the pic may not be accurate enough and failed to realize that it could simply serve as a counter running off a crystal. How do I know I am getting the newest, improved version of the ?
dataheet Replacing a 4 pin leaded inductor with a 2 pin Started by gkmaia Yesterday at Just saying hello Started by MichaelaJoy Yesterday at 6: As a beginner, reasonable accuracy is good enough for now.
No, it’s 2Hz only, to get 1Hz you need another divider. If you are lucky, any internal damage has been confined to the driver for pin 7, which you aren’t using.
To create a one second time base, I went looking for this: Could I just not purchase an oscillator?
Another solution is a Hero Banned May 18, That will cause a significant current to flow through the IC and also cause its temperature to rise, as you measured. Not everyone likes or wants to use microcontrollers and i understand this, so another solution is to use an LM and a capacitor and a few resistors to make a ratasheet oscillator.
The logic gate just after the RESET signal is an inverter the remains of other, removed, signal lines make the inverter symbol a little unclear.
Then i have to ask, why the datasyeet Could test it out with that. Sign up or log in Sign up using Google. The Maxim part is expensive because it is Temperature Compensated, so it has circuitry that is probably individually calibrated at several temperatures. Again, kudos to brhans for spotting the problem first.
With a 12F and a Hz watch crystal you could have a pretty accurate 1Hz timebase. Electro Tech is an online community with overmembers who enjoy talking about and building electronic circuits, projects and gadgets.
How accurate do you need the timebase? You shouldn’t be grounding it. I can not help but smile.
CD4521 24-Stage Frequency Divider IC
I’ve looked at that inner circuit diagram many times for various reasons, but I totally overlooked the issue with Pin 7! Your information is very interesting.
Also, as I mentioned, these ICs might already have been partially damaged, and require replacement if you want to be confident of their future behaviour and reliability. I have several pics and a programmer and am somewhat aware of it’s possibilities in this case.
Heck, I could even tweak the count to adjust it’s accuracy I’ll bet. That lets the circuit compensate for the temperature drift of the crystal, resulting in an oscillator that is far more accurate than a standard watch crystal. You must log in or register to reply here. If the code is adjusted for the particular RC oscillator on chip, the accuracy can be very very good and be stable at room temperature too with only a tiny variation for plus and minus say 10 degrees C.
Hero Banned May 19, Click here to register now. The reason i ask is because many times a person is looking for a one half Hertz oscillator but they ask for a 1Hz oscillator. If you use the internal RC oscillator, you dont even need a crystal or external oscillator.
If you have an 8 pin PIC laying around you’re all set to go However, I think your LM suggestion bears serious looking at because the datasheet says it will operate over the full military temperature range.
The difference is, if the oscillator is going to be used as a 1Hz time base for say a frequency counter, the frequency really needs to be one half Hertz, not 1Hz, because the period of time the 1Hz wave is high is only one have second and they really want 1 full second. Cheap, easy, and accurate. That is fairly inaccurate in the short term, but is corrected so that the long-term drift is zero, as many electric clocks use the mains frequency as a reference. Diver Well-Known Member May 18, Price depends on stability, and can be as good as 0.
Also, I varnished over the cut with nail polish to prevent accidental contact due to oxide growth.