Biasing at Split pin of CAN transciever

Thread Starter

Shashwat97

Joined Apr 15, 2019
13
I have a scenario where in project I'm required to bias split pin(mid point where we employ split cap ) between 2 60ohms termination resistor at 2.5V.
What can be the reason of the requirements any idea??
 

nsaspook

Joined Aug 27, 2009
7,585
https://www.silabs.com/community/blog.entry.html/2017/11/29/timing_101_the_case-Yf00
https://www.nxp.com/docs/en/application-note/AN10211.pdf
4.4
Common mode stabilization, SPLIT pin The high impedance characteristic of the bus during recessive state leaves the bus vulnerable to even small leakage currents, which may occur with unpowered transceivers or ECUs within the bus system. As a result the common mode voltage can show a significant voltage drop from the nominal VCC/2 value. After transmitting the first dominant bit of a CAN frame (Start-of-Frame Bit) the common mode voltage would restore to its nominal value. This would lead to a large common mode step and an increased emission. The TJA1040 provides a common mode stabilization by offering a voltage source of nominal VCC/2 at the pin SPLIT (Figure 7). The common mode stabilization improves the EMC performance of the TJA1040 significantly. Its use is recommended if there are unpowered nodes while other nodes keep communicating.
 
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