digital bus transceiver...

Discussion in 'Homework Help' started by dtvonly, Dec 18, 2013.

  1. dtvonly

    Thread Starter Member

    Dec 14, 2012
    43
    0
    the internal circuit schematic of any typical bus transceiver shows that input A is buffered to output B. My question is: if my Vcc is 5V and my input to A is 3.3V, will my output B be 5V? If not then is there an IC that does level translation to Vcc as well? thank you.
     
  2. shteii01

    AAC Fanatic!

    Feb 19, 2010
    3,392
    497
    Buffer does not alter input. 5 goes in, 5 comes out.

    Level translators exist. They are commonly called level shifter.
     
  3. MrChips

    Moderator

    Oct 2, 2009
    12,446
    3,361
    The input of a digital bus transceiver has low-to-high and high-to-low switching thresholds. Once those thresholds are met the output will switch according to the supply levels (i.e. between Vcc and GND.)

    Hence the 0-3.3V input will translate to GND to Vcc output, 0 to 5V in your case.

    The opposite is not necessarily true. If you are driving 0-5V input into a 3.3V device you have to make sure that the device is protected from the over voltage at the input.
     
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