Can TJA1043 detect short circuit to battery voltage with CANH, CANL and change ERR PIN

[hyungjinjoo]

TJA1055 (Low Speed Fault Tolerant CAN Transceiver) can detect short-circuit to battery voltage on pin CANH and CANL respectively in normal and low power mode. In the datasheet, however, TJA1043 seems to detect short-circuit by monitoring the differential voltage of CANH and CANL. Is that right? or is TJA1043 also capable of detecting short-circuit of each CANL and CANL seperatively?

And one more question is that what is the voltage of CANL and CANH in normal mode and sleep mode?

[PetrS]

Hi,

Yes, the TJA1043 is monitoring differential voltage.

The bus failure diagnosis is discussed in AN1014 in chapter 6.6; http://www.nxp.com/documents/report/AH1014_v1_4_Application_Hints_TJA1042_43_48_51.pdf

In sleep mode the CANH/CANL pins are biased to GND.

In normal mode the CANH/CANL pins are biased to Vcc/2. Dominant output voltage is defined as following

 

BR, Petr