TCAN1043HG-Q1: Components Evaluation in 5Mbps

Hi Beida,

Thanks for your patience while we were out yesterday.

Beida Song said:

1. Customer wants to know that what's the function for C2/C6/R9/R14?

R9, R14, C6 are used for the split termination option for the EVM. The board also includes single ended termination options (R8, R11) for more convenient control of termination during evaluation, but a typical application would only have one source of 120-ohm termination for an end node (high impedance or no termination for intermediate nodes). Generally we recommend use of split termination in applications that can afford the space and cost of passives as it provides better filtering for the common mode. 

* from TCAN1043H datasheet 

C2 and C7 are bus capacitors that are used to filter out high frequency single-ended noise on the CAN lines. These are typically valued between 10pF - 100pF in application. The pads on the EVM can also be used to simulate a capacitive load on the bus. 

Beida Song said:

2. Is the requirements different for L1 between 2Mbps and 5Mbps? Whether TI have calculation tools for components parameters evaluation?

Common mode chokes for CAN networks are typically valued at 51uH or 100uH. Most systems will be able to use either, but naturally lower inductance values will be preferred for higher data rate systems. I often see and test with a 51uH CMC: TDK ACT45B-510-2P.

Let me know if you have any more questions. 

Regards, 
Eric Schott