TJA1043

[zyc0211]

Hi all,

On power-on, only Vbat is present , VIO and VCC is under-voltage,and then i send a CAN freme(101)to remote wake TJA1043,but the INH is not HIGH,it is also floating.

[JozefKozon]

Dear Zhao,

please share your schematic with voltage levels and part values. 

Please share a scope from an oscilloscope of the wake-up pattern you send via the CAN bus. 

JozefKozon_0-1706685955280.png

With Best Regards,

Jozef

[zyc0211]

zyc0211_0-1706689281448.pngzyc0211_1-1706691812672.png

[JozefKozon]

Hi Zhao,

thank you for the scope and for the schematic. The wake-up pattern is correct. 

What is the VBAT voltage? Recommended is 12V, but the TJA1043 will work with VBAT from 4.5V to 40V.

JozefKozon_2-1706699024448.png

If there is an undervotlage on either VIO or VCC, the TJA1043 will switch to Sleep mode. In sleep mode, the INH pin is always floating. 

JozefKozon_0-1706699479130.png

JozefKozon_1-1706699547053.png

To be able to wake up the TJA1043 from Sleep mode and pull the INH pin high, you need to bring the voltages on the VCC and VIO pins according to the Table 1.

JozefKozon_2-1706699660369.png

With Best Regards,

Jozef