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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CD4521 24-Stage Frequency Divider IC

You just copy timer0 bit 7 to an output pin with a prescaler. After a bit of a learning curve, I got it to alternately blink two leds and was so happy I let it run for an hour. So, sure, if someone would like to post a link for a tutorial or sample generic code of their favorite one for this C language please.

I have a peculiar problem involving the CD frequency divider of which I use two in a redundant configuration as shown in my schematic snippet below: Could I just not purchase an oscillator? After reading a bit to understand how these things work, I was thinking I could use another 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.

One Second Time Base | Electronics Forum (Circuits, Projects and Microcontrollers)

Hero Banned May 19, The MCU is still an option but it would need a crystal so the counter might be more convenient. It’s gotta be one of the simplest programs you can do.

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It depends on how much accuracy you really need. Therefore, after each going through an inverter, the two inputs to the NAND gate in the diagram are both High, and its output is Low. To participate you need to register. 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.

Thank you for the analysis and for taking the effort to prepare such an exhaustive answer! If you have an 8 pin PIC laying around you’re all set to go I’ve edited the original cf4521 from the TI datasheet that you linked, to remove extraneous parts. Cheap, easy, and accurate. I’ll look out for this issue from now dagasheet. The temperature is the same between the two units and they both operate reliably so far. This is where my inexpierence shows. This site uses cookies to help personalise content, tailor your experience and to keep you logged cdd4521 if you register.

Just saying hello Started by Dc4521 Yesterday at 6: Therefore its output is now High.

Sign up using Facebook. Boncuk New Member May 18, Price depends on stability, and can be as good as 0.


Therefore you are effectively trying to cause a short-circuit at pin 7 of the IC, limited mainly by the IC’s output driver current capability.

LM oscillator is the simplest and cheapest 1 cap, four resistors and maybe a potentiometer for perfect adjustment 2. The pic stuff is something I will be working on in the future. That’s cheap and low power compared to a Rubidium oscillator. It is possible that this has already damaged the IC, to a greater or lesser extent. If you are lucky, any internal damage has been confined to the driver for pin 7, which you aren’t using. Is there a way to bring your cv4521 down to 5 volts?


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Started by fastline Yesterday at 8: Datasheett starter jack Start date May 17, I’ve actually used this solution though and it isnt too hard to build, and a high accuracy oscillator can be found if needed. I could have used 60hz from the mains, but wanted to be independent of an external source. I like Hero’s suggestion because, if I understand correctly, it is most likely as accurate as any watch oscillator and simple to build without the need of additional equipment such as a frequency counter which I do not have for calibration.

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. The circuit I posted also has 0. I do have a good scope once I learn to use it.

Below is the relevant part of my PCB layout – your wisdom will be much appreciated! Email Required, but never shown. Is this a different ?