1
\$\begingroup\$

I need to implement a pull-down resistor for a project, but I am unsure of what resistor to buy. My circuit deals with 5v inputs. Essentially, I am trying to make this: keypad scanner.

Here is a store where I can choose from 1/4, 1/2, 1W, etc resistors:Creatron Inc.

Which one would be the best?

Also, in the circuit in the link above, I am unsure if there needs to be a VCC. I assume the input pins C0, C1, C2 are enough, but please correct me if I am wrong.

\$\endgroup\$
1
\$\begingroup\$

Since your project will be interfaced with a keypad for a decoder, i think a 1/4 resistor would do just fine. This is because digital applications usually just play around the milliampere currents and with a rating of 0.25 watts(1/4) this even gives you an allowance. Just use the correct resistance, for this case you just have to avoid going below 100 ohms. You would commonly see 1W resistors for power supplies since it involves higher power ratings (higher voltage and current).

And yes no need to add VCC for the keypad; the C0, C1 and C2 pins are the ones supplying the voltages (this depends on your programming) for the keypad. :)

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.