TPS65987D: How to control BQ25703A via I2C3 of TPS65987D ？

user5821506

Part Number: TPS65987D
Other Parts Discussed in Thread: BQ25703A, , BQ25703

How to control BQ25703A via the I2C3 of TPS65987D？

The I2C3 of TPS65987D is connected to bq25703 in my design.

I have changed all the register according to the SLVAE18.pdf ,and set the I2C3 as master,but i can’t see any waveform by the oscilloscope on the I2C3 scl & sda. Of course, BQ25703 is also not set successfully.

the current setting of my tool:

Please help us to solve this problem.

over 6 years ago

0 Eric Beljaars over 6 years ago

TI__Mastermind 36756 points

Hi Zhiyi,

Your settings look mostly correct to me. Thank you for following SLVAE18. I would suggest adjusting the App Config Binary Data Indices (0x62) to all be under "Common I2C Record". Additionally, please double check the I/O Config register to ensure that GPIO 4 and 5 are multiplexed to I2C master use for I2C3.

Thank you,
Eric

0 user5821506 over 6 years ago in reply to Eric Beljaars

Prodigy 190 points

I have changed the 0x62 config according to your suggestion. And i'm sure the GPIO 5 and 6 are multiplexed to I2C3.

but the I2C3 master still can't work.

Here is my prj file:

/cfs-file/__key/communityserver-discussions-components-files/138/TPS65987DDH-_2800_Standard_2900_-UFP-DISPLAYPORT_2B00_-BQ25703-5_2D00_20.zip

please help me check it.

thanks

0 Eric Beljaars over 6 years ago in reply to user5821506

TI__Mastermind 36756 points

Hi Zhiyi,

Thank you for checking the GPIO mux config. The rest of the configurations look ok to me. Can you confirm that you have the I2C3 lines pulled up to LDO_3V3 using pull-up resistors? Additionally, can you attach an I2C analyzer on the I2C3 lines? It is possible that the I2C slave is NAKing messages from the 87D.

Thanks,
Eric

0 user5821506 over 6 years ago in reply to Eric Beljaars

Prodigy 190 points

Hi Eric,
Thanks for your reply.
I have pulled the I2C3 lines up to LDO_3V3 by 3.9Kohm, but I still can't see any waveform on I2C3 lines with my oscilloscope .
In addition, the chip is tps65987ddh，does it matter？
Do you have any prj file that have used I2C3？I can program it into my board . In order to verify that I2C3 port can work properly.

0 Eric Beljaars over 6 years ago in reply to user5821506

TI__Mastermind 36756 points

Hi ZhiYi,

I'm not sure why you are not seeing the I2C3 working, your configuration looks correct. Please find below an example project using TPS65987D and BQ25703A that I have tested with 2 EVMs.

88DH Power Bank.pjt

Thanks,
Eric

0 user5821506 over 6 years ago in reply to Eric Beljaars

Prodigy 190 points

Hi Eric

The example project is still using I2C1. I have already tried the I2C1 by jumper of my EVM board, use the I2C1 project, the I2C1 can work.

But if i use I2C3, use the I2C3 project, it can't work. Can you test the I2C3 on your EVM by using i2C3 project? It would be ok if any waveform happens.

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TPS65987D: How to control BQ25703A via I2C3 of TPS65987D ？