Hello

I need to connect an LCD that uses a 5V logic levels(T6963C) bus to a 3V3 Cyclone II

can someone tell me the simplest and safest way to do.

Tanks a lot

 

I would suggest a family of gates that can use any Vcc from 1.65V to 5.5V with TTL thresholds and 5V tolerant inputs.

http://www.onsemi.com/pub_link/Collateral/MC74VHC1GT50-D.PDF

These work well in this application. This link really ought to be sticky as this is about the 10th time I've mentioned it.

 

You could also use a logic level translation IC.
Dallas/Maxim has a helpful article on this:
http://www.maxim-ic.com/app-notes/index.mvp/id/3007

 

You will most likely find it works with an almost direct connection.

Fit 1K resistors in line with the pins on the LCD that can function as outputs (D0-D7?) to limit the current fed back to the MPU, and fit small schottky diodes from the MPU end of each resistor to the MPUs 3.3V supply.

 

Hi
Thanks a lot for the replys