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Re: can i use 5V device as this ways?

Started by David Hawkins November 13, 2007
>> For some reason, i want to use 5V devices (for example: AM26LS31) in my
>> circuit.

Its a 5V line driver.

V_IH(min) = 2V

The input current for high and low does not exceed the 4mA drive
current of the LPC.

You can drive this part fine with the LPCs 3.3V I/O logic.

If you want to interface 5V outputs to the LPC, you will need to
use a 5V tolerant 3.3V buffer between the 5V I/O and the LPC.

If you have a few lines you want to read, you can use TinyLogic
parts from Fairchild. As soon as you get to 8-bits, you can
use 5V tolerant 3.3V '244 buffers. Eg. TI LCX (I think),
Pericom LPT, etc. Lots of mfgs have them.

If you need bidirectional protection, you can look at
BusSwitches.

Regards,
Dave

An Engineer's Guide to the LPC2100 Series