topic Re: TJA1021 K-LINE compatibilty in MPC5xxx

TJA1021 K-LINE compatibilty

vinodhodal — Thu, 07 Jul 2016 18:01:33 GMT

Hi,

In TJA1021 datasheet it is mentioned that this part is K-line compatible. Can we use this part for OBD VTS application?

Does this part support K-line ISO 9141 & ISO 14230 (KWP protocol)?

regards

Vinod

Re: TJA1021 K-LINE compatibilty

lukaszadrapa — Fri, 08 Jul 2016 07:26:44 GMT

Hi,

take a look at attached document, section "5.4 ISO 9141 (K-Line) compatibility".

Regards,

Lukas

Re: TJA1021 K-LINE compatibilty

vinodhodal — Fri, 08 Jul 2016 08:15:53 GMT

Hi Lukas,

Thanks for reply.

Please clarify below more points:

1.We want to use TJA1021 on OBD port of vehicle to get vehicle information. Do we need to add diode and Rmaster resistor between VBAT & LIN line. Is this a Master node application?

2. Application notes AH1103 clarify on K-Line ISO 9141 compatibility but does not clarify on another K-Line protocol ISO 14230 (KWP). Will TJA1021 work well for ISO 14230 KWP (Keyword protocol)?

regards

vinod

Re: TJA1021 K-LINE compatibilty

lukaszadrapa — Fri, 08 Jul 2016 10:30:16 GMT

Hi Vinod,

1. If it is the peer to peer LIN communication in OBD application, the module in the vehicle OBD port is usually working as the slave node. So no need about the diode and Rmaster.

But I propose to double check with target CAR OEM requirement in the real project. If it is not possible, then just leave the position about the diode and Rmaster and set it as the not install component.

2. Depends on the working bit rate. No LIN transceiver is fully compliant to the K-LINE, but compatible. You can see the difference from the document. So I think TJA1021 can work well for K-Line protocol ISO 14230 (KWP) with bit rate 10 k bit/s.( I received one case before from some customer about TJA1021 for K-Line protocol ISO 14230). But if the bit rate of K-line is above 20kbit/s, TJA1021 probably cannot support.

Regards,

Lukas