Newbie question

[Shaders]

Hello,
Soory for my bad english
I am under development of the detector.
With is your opinion you he possible to install a 74HCT221 in the place of the 74HC221? Or, must I change supplier of components

The HCT supports a input tension of 5 volts and seem a little slower
According to documentation.


In advance thank you for your answer


Cordially
shaders

[Shaders]

I found the answer at :
http://www.semiconductors.philips.co...USER_GUIDE.pdf

soory to have made an useless post

[Carl-NC]

The "HC" in the part number means high-speed CMOS, while the "T" means TTL-compatible. I know that you cannot use the 74LS221, which is a pure TTL (bipolar) part, because the I/O logic swings are insufficient. If the HCT I/O behaves like the LS, then it probably won't work.

- Carl

[Shaders]

Obviously, the principal change is the circuit input voltage and the switching time. Moreover, the HCT has an additional transistor (certainly for the TTL compatibility) My component supplier does not sell a HC but only HCT. I will test as that... has will see well if that working good. Thank you to have answered quickly, and cheer still for this project.

[Shaders]

Obviously, the principal change is the circuit input voltage and the switching time.

Moreover, the HCT has an additional transistor (certainly for the TTL compatibility)

My component supplier does not sell a HC but only HCT. I will test as that... has will see well if that working good.

Thank you to have answered quickly, and cheer still for this project.