topic Re: IMX281 CAN Bus output in i.MX Processors

IMX281 CAN Bus output

annyli — Fri, 11 Sep 2015 06:54:43 GMT

The CAN_RX and CAN_TX can be connected to the CAN chip directly in my opinion. So why the EVK board use a buffer chip before CAN chip? Is it necessary?

Re: IMX281 CAN Bus output

MartinHo — Fri, 11 Sep 2015 09:49:38 GMT

The Buffers are used as level shifter (3.3V to 5V and 5V to 3.3V) if You use a 3.3V CAN-Bus Transceiver (for example SN65HVD232 from TI) they are not needed, or if You use a 5V type with TTL Inputs, You only have to reduce the RX output to 3.3V level .

Martin

Re: IMX281 CAN Bus output

igorpadykov — Fri, 11 Sep 2015 11:27:21 GMT

Hi anny

you are right: they can be connected directly.

EVK board was designed to provide as much possible connections

as possible to test all available interfaces and its options.

These buffers were added for flexibility, for example MX28 EVK board supports

up to 4 NAND flash ICs (CE0, CE1, CE2, and CE3).

However, the 0 ohm options for CE2 and CE3 are disconnected by

default (they are used for CAN).

Best regards

igor

-----------------------------------------------------------------------------------------------------------------------

Note: If this post answers your question, please click the Correct Answer button. Thank you!

-----------------------------------------------------------------------------------------------------------------------

Re: IMX281 CAN Bus output

annyli — Tue, 15 Sep 2015 02:47:26 GMT

OK, I understand, thank you!:smileyhappy: