How to interface 3.3V logic with 5V logic

[zhiling0229]

74lvc425

Hi guys,

Newbie here. I am trying to interface a microcontroller 3.3 V logic HIGH with 5 V logic HIGH microcontroller. I required to interface 18 parallel pins from 3.3 V to 5 V logic. I used a chip 74LVC425 to do the interfacing. I was wondering is there any easier method to do the interfacing?

Thanks

 

[IanP]

If you need to support both directions then the LVC(LVT)245 is the simplest solution ..

Regards,
IanP

 

[roofingboom]

use line level buffers for 3.3 and 5 volts. As per what ianp said those are line level buffers. Use CMOS going one way and use TTL line buffer going the other way. The thresholds of each do level translations.
Any other questions let me know

when going from 3.3 input to 5v output logic use TTL line buffer
TTL translates anything above 2.4 volts as logic 1 and anything below .5 as a logic 0.

use cmos going the other way

 

[deepu_ttc]

y can't you use transistor at the output of the low voltage µc as a switchof 5V

 

[kovic]

try to use serial resistance 200 or 220R between 3.3 and 5V. it may solve the problem.

 

[tnmk]

You can use level shifters or translators, many vendors have these ICs. pls check in the web.