LCD Logic levels adapter

Discussion in 'General Electronics Chat' started by MiguelF, Feb 2, 2010.

  1. MiguelF

    Thread Starter New Member

    Jan 19, 2010
    2
    0
    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
     
  2. Papabravo

    Expert

    Feb 24, 2006
    10,152
    1,793
    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.
     
  3. SgtWookie

    Expert

    Jul 17, 2007
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    1,728
  4. rjenkins

    AAC Fanatic!

    Nov 6, 2005
    1,015
    69
    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.
     
  5. MiguelF

    Thread Starter New Member

    Jan 19, 2010
    2
    0
    Hi
    Thanks a lot for the replys
     
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