Automotive Airbag IC- L9678P-S Evaluation Board Schematic

[Sharma]

Hello All, 

 We planned to use STM  Airbag IC- L9678P-S for one of our automotive application development. We intended to use L9678P-S having PSI5 /SPI/I2C sensor interface   using Evaluation Board set up . Can some one share the Schematic of the EVB L9678P-S board . 

Thanks in advance.

Regards

Sharma

[Peter BENSCH · Accepted solution]

Welcome @Sharma, to the community!

The  L9678P-S is an automotive device whose tools and full documentation are usually only available from your local distributor or STMicroelectronics office.

Hope that helps?

Regards
/Peter

[Sharma]

Hello Peter,

Appreciate your quick response on my query. I am located in Bangalore/India. Is there a possibility for you to provide ST Bangalore/India contact email ID for  me to get connected and  avail  their help .

[Peter BENSCH]

All contact details can be found with the URL if you select the contact type and your region:

https://www.st.com/content/st_com/en/contact-us.html

[Sharma]

Hello Peter,

 We received the L9678P EVB schematic from the distributor and working on building an application for air bag system.

At the beginning, we are trying to make the EVB up running for the SPI/PSI5 communication. In our set up, we had connected  ADI chip set (processor-master ) to SBC L9678P-S for SPI communication at 5 Mhz clock. VDDQ supply is set to VDD3V3 since the micro operates at 3.3V.

   We could able to establish the SPI communication between  ADI chip set (processor-master ) and  L9678P-s(Slave). We were able to set/turn on  the  power supply pins on L9678P-s like ERBOOST(33v), VSUP(6.8V). by sending the following SPI write messages.
 Input supply voltage VBat = 12V , Watchdog Enabled and  VRESdiag jumper on the EVB set to  VRBOOST.

Here are the SPI messages we are sending from ADI chip set to  L9678P-S in enabling the power supplies:

SPI Register address $01  SYS_CFG         SPI Message :  00 02 55 ED    

SPI Register address $02  SYS_CTL          SPI Message :  00 05 1E E0

   After sending the above SPI messages, L9678P is able to set the ERBOOST voltage to 33V and VSUP to 6.8Volts. After this step, we are trying to enable PSI5 communication on channel 0  by turning ON the RSU0 supply  by sending the following SPI messages.

SPI Register address $4A  RSCR1          SPI  Message :  00 94 00 00  

SPI Register address $4E  RSCTRL       SPI   Message :  00 9C 00 02

    After sending above SPI messages, we tried to measure the voltage at RSU0 terminal using multimeter and it always shows 0 volts ( P.N : PSI5 sensor is connected  between RSU0 and GND ). Looks like the PSI5 channel0 power supply controlled through register RSCTRL   bit 1 - CH0EN  is not getting enabled/set. Can you please help us out in resolving the RSU0 power supply issue for  PSI5  axis accelerometer sensor interface.

Thanks in advance

Regards

Sharma.

[Peter BENSCH]

Your first question was about the documentation for this device, but my answer also refers to the support for it. If you have any questions, please contact the local distributor again, or alternatively the personal online support OLS.

Regards
/Peter

[Sharma]

Hello Peter,

 Thanks for your input.  Sorry to say that ST local support is very very minimal or No. Hence we need further technical support in resolving the issue. As you indicated in the email I will post my query in OLS - ST.

Regards

Sharma