how can i wakeup TJA1040 use CAN

[xsfan]

i need to wakeup a TJA1040 through CAN and i found the tBUS value is (0.5us~5us),so when i use the 500kbit/s CAN ,it means that any one bit in the message will cost 2us,and may lead to generate a wakeup signal(if the value is fit).

so,it means that any message on the bus will wake up the TJA1040,am i understand right?

but if on the car,the meter will send some messges all the time (even if IGN OFF),so during the standby mode the TJA1040 will always receive a wakeup signal,and then(MCU) wake up the TJA1040 ,so the TJA1040 stand by mode seems do  not work .

[lukaszadrapa]

Hi,

yes, that's correct. Any message on CAN bus will lead to wake up in this case.

If it is not suitable behavior for your application, there are other transceivers like TJA1041A or TJA1044:

http://www.nxp.com/documents/data_sheet/TJA1041A.pdf 

See the "7.1 Wakeup via bus":

http://www.nxp.com/documents/application_note/AN00094.pdf 

And

http://www.nxp.com/documents/data_sheet/TJA1044.pdf 

("7.2 Remote wake-up (via the CAN bus)")

Regards,

Lukas