how to interface 3V3 pins with 5 V logic ?

[mehmet.karakaya]

Posted on September 07, 2010 at 09:44

how to interface 3V3 pins with 5 V logic ?

[Tesla DeLorean]

Posted on May 17, 2011 at 14:05

It's a universal topic, try Googling.

Depends on the type of logic you are interfacing to (VOL/VOH/VIL/VIH), you can add buffering logic, or resistor networks, or use open-collector outputs and pull ups. Some of the STM32 pins are 5V tolerant, check the TRM.

[Andrew Neil]

Posted on May 17, 2011 at 14:05

As clive1 says, a direct connection may be acceptable - see the datasheets of all devices concerned.

In extremis, specific logic-level translator chips are available. Here's a couple of App Notes from NXP which might be helpful: 

http://ics.nxp.com/support/documents/interface/pdf/an10441.pdf

http://ics.nxp.com/support/documents/interface/pdf/an97055.pdf

[Andrew Neil]

Posted on May 17, 2011 at 14:05

As clive1 says, a direct connection may be acceptable - see the datasheets of all devices concerned.

In extremis, specific logic-level translator chips are available. Here's a couple of App Notes from NXP which might be helpful: 

http://ics.nxp.com/support/documents/interface/pdf/an10441.pdf

http://ics.nxp.com/support/documents/interface/pdf/an97055.pdf

[Andrew Neil]

Posted on May 17, 2011 at 14:06

... as Texas Instruments calls them:

http://focus.ti.com/lit/ml/scyb018d/scyb018d.pdf