Hello to all the experts at NXP:
We have two questions regarding the TJA1043 chip used in our project:
1. When our controller enters sleep mode, the MCU pulls down the STBN and EN pins of the 1043 to enter standby mode. At this time, the VBAT of the 1043 is 24V, VCC is 5V, and VIO is 3.3V. At this time, INH should still be at a high level of 24V, right? If a CAN message arrives on the CAN bus at this time, the 1043 will be woken up. During this period (from standby to normal), will the level on INH remain high, or will there be a high-low-high transition?
2. In a 24V system, during short-power supply testing, the power supply voltage is 32V. Using a controller with TJA1043 and CAN configured as a terminal node (120ohm), during CANH short-power supply testing, according to Fig. 39 of AH1014:
What is the maximum IP value? What is the resistance value of the resistor in the red box in the image above? Considering WCCA, what power rating should I choose for my RT/2 resistor?
Please help me answer this, I would be extremely grateful!
Okay, thank you so much for your reply!
Hi
1: Always high level
2. Normal Applications : 60 Ω, 0.1 W / 0.125 W is generally sufficient for normal communication power consumption. RT/2 power is determined by the customer's short-to-battery test conditions. The diagram in the NXP documentation illustrates the failure mechanism, not the RT/2 power rating. We cannot provide specifications beyond those in the datasheet for the TJA1043.