MK66FN2M0VMD18 digital 5v input tolerant

[henrynguyen]

Hello,

we have used the  MK61FN1M0VMD12  part in the past and its spec said very clearly that all digital IO pins are 5V input tolerant.  see attachment for MK61 snap shot.

now, we are looking at MK66FN2M0VMD18 device but can not find any 5v input tolerant on the data sheet.  we are surprised because the MK61F and MK66F should be the same family.

can you please clarify?  This is very confusing on why the same family part does not have the same 5v input tolerant.

Thanks and Best Regards,

Henry Nguyen

[nxf77486 · Accepted solution]

Hello @henrynguyen ,

The assumptions are correct all the Kinetis pins, with exception of the specified have an input mode of 5V tolerant.

We will review out documentation in order to updated.

[myke_predko]

Hi @henrynguyen 

What you're showing is exactly right, all the Kinetis pins, with the exception of the specified ones, in input mode are 5V tolerant.  I recommend a 1k resistor between the 5V output to the Kinetis input pin to minimize any potential current flow from the output into the Kinetis.  

We had a discussion on using the pins as Open Collector outputs and you can see it here:  5v Tolerant pins as Open Collector Drivers). 

Good luck!

[henrynguyen]

Hi Myke_predko

thank you so much for your input.  
However I am still uneasy because I am not sure why NXP did not spell this out explicitly for K66F data sheet.  
In our application, the RXD pin from CAN transceiver drives a digital 5v to the K66F input.  The current is low but it is 5v and the K66F VDD is 3.3v.  

can someone from NXP please confirm if our assumptions are right and the data sheet will be updated to reflect this?

thanks

Henry