What is a CD4074?

How dumb are you ?

Has the name Google eluded you all these years ? I take it, that's a radio ham ID, yet you've never heard of 400 series CMOS that came out - oh - 40 years ago ?

Graham

4000 series.

Before that there was 54/74 series TTL and before that 930 series DTL logic.

Never met any RTL, except discrete simple implementations.

Graham

It's not in my ancient Philips printed 4000 series databook but it's interesting that these guys claim to have some for sale.

Was it a typo though and he meant CD4047 ?

Graham

On Fri, 16 Jan 2009 17:30:21 -0500, David Snowdon put finger to keyboard and composed:

Why not experiment with one of them by connecting 4K7 pullup resistors to each of the input and output pins? Then do the same with pulldown resistors. In this way you'll construct a partial truth table. A pin which goes low while connected to a pullup resistor, or high while connected to a pulldown resistor, would be an output. You *may* also be able to differentiate between inputs and outputs by seeing which pins "float" when disconnected. I'm assuming the power pins are the same as for other CD407x parts.

- Franc Zabkar

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This assumes that it is, in fact, a digital device and that it doesn't use registers.

I'm still waiting to see a photo of it.

I'm almost willing to bet it's something simple, like reversed digits. There was the CD4047, a monostable/astable multivibrator. 14pin package, which of course is one extra bit of information that helps to define an IC.

Michael

Eeyore wrote in news: snipped-for-privacy@hotmail.com:

Maybe smarter than you? That was the easy bit. Now look for that actual number. Apart from the vague promises of various brokers who might as well be the undiscoverable aether, the part doesn't appear to exist. I looked at a few listings of CMOS logic IC's and that one always draws a blank. Michael Black's suggestion makes sense, a misread of an existing number.

Eeyore wrote in news: snipped-for-privacy@hotmail.com:

Has it really NEVER occured to you that those guys are full enough of shit that they'd fill in gaps in apparent sequences just to make it look like they have everything? No wonder counterfeiters and shysters can profit so easily when that kind of gullibility persists.

On Sun, 18 Jan 2009 03:32:26 -0600, Lostgallifreyan put finger to keyboard and composed:

I must confess that had never occurred to me, but now that you've suggested it, I've confirmed that other non-existent (?) parts also show up in the listings, eg CD4091, CD4092, HEF4074, CD4083, CD4084, CD4088. However, all except the last example could be accounted for by typos in the last two digits.

The gap in the CD407x sequence (and others) begs the question, how are part numbers chosen and why was 4074 not used? Are certain numbers reserved? Do they reflect prototypes that never made it into production?

- Franc Zabkar

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Never saw any in the field. Back in '69 or '70, though, I built an 8-bit ripple counter with some Motorola RTL DIPs, an incandescent(!) indicator hanging on each stage.

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Michael

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Lostgallifreyan wrote:

Why would they do that for part that doesn't exist and for which there can therefore be no demand ?

Graham

Eeyore wrote in news: snipped-for-privacy@hotmail.com:

Ask them if you want their answer. Not that it's likely to help you. Work it out yourself. Ok, I'll spell it out for you. They see a range with apparent gaps. They don't know if the missing numbers mean real parts or not, so they fill the gaps in so their listings have a higher chance of returning as Google results. Obviously if the part doesn't exist then it's less likely to get called for, but they don't kmnow that, do they? Easier for them to add it to the list and be done with it. Especially if it appears via one of theor own search tools as the result of a typo. Again, they don't know what's real all the time, they just add anything that looks like it should be added. Just LOOK at one of their wretched lists some time, that alone should convince you of this. All numbers and no data.

That is China. Yes, they can make any IC you want. Just tell them and they will burn the correct text on any dip IC. Fake of course.

p

My 1977 Fairchild CMOS Data Book shows that CD4074 was skipped. As was

4079, 4080, 4083 etc.

Tht 4073 was a triple 3-input AND gate and the 4075 was a triple 3-input OR gate.

Al

When you google for the part, you find a lot of Chinese companies offering them. So they must all be fake?

Or another manufacterer picked up the 4074 name?

P.

P. wrote in news: snipped-for-privacy@4ax.com:

Don't ask! Ultimately you'll be told what someone thinks you want to hear. That's why those shysters exist, they know there are always people who do this. If you really want to know, look for the details. Once you find a detailed description, maybe even a data sheet, and perhaps even a second primary (manufacturing) source of such data, then you can assume it exists After all, it works for damn near all parts that do. If someone with lots of numbers and no data offeres you stuff as rare as hen's teeth, don't touch them with a ten foot pole. No beanstalk is EVER going to grow from those beans.

On Tue, 20 Jan 2009 02:36:26 +0000, Eeyore put finger to keyboard and composed:

This thread is starting to look like Monty Python's Bookshop Skit:

- Franc Zabkar

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