Re: CD4050AE vs CD4050BE

On 27 May 2007 14:06:04 -0700, the renowned logjam <grant@xxxxxxxxxxx>
wrote:

I have a project that requires a 4050. I bought around 50 CD4050BE
ICs, but none of them work in place of the old (vintage 1975)
CD4050AE.

I lifted legs 2 and 3 out of the IC socket, attached my scope to leg 2
and connected leg 3 to leg 1. This should have caused pin 2 to go
high according to the data ***. The input threshold for high is
supposed to be 3.5v. Pin 8 is a good hard ground. The voltage supply
is 5.02v. The CD4050BE (new ones) were pulling the inputs down from
4.5-5v down to 2.5v (there is a 47ohm resistor in front of the
inputs). With the CD4050AE part the inputs are not pulled down.

So either I got an entire tube of bad parts, or the AE / BE indicates
something important? I haven't been able to find a data ***
specifically for the CD4050AE.

I have tested a vintage 1975 MC14050CP is known to work in place of
the CD4050AE for this application.

I will continue to try to find the data ***.

Right now I am going crazy. I have tried 8 or so parts from the
tube. I wouldn't imagine the whole tube would be bad. Even in a test
circuit I can't get anything out of them... : ( Even if the voltage
was not high enough to be "high", it was sure loading the inputs a
lot...

Thanks,
Grant

Where did you buy these parts?


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@xxxxxxxxxxxx Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
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