BQ78350-R1: BQ78350-R1

Tang Vy

Part Number: BQ78350-R1
Other Parts Discussed in Thread: BQSTUDIO, EV2400, BQ78350

Hi,

I am using MCU STM32F1 to communicate with BQ78350-R1 through SMBus pins but it only send out the address 0x16 and then nothing happen. I have wired VCC to +2.5V, VSS to ground, SMBD and SMBC to I2C ports of the MCU (SDA and SCL) and using I2C of the MCU with 90kHz frequency to communicate with it, I have also tight up SMBD and SMBC pin with 10k Ohms pull-up resistors with +2.5V sources each. Am I doing anything wrong?

Thank you.

over 4 years ago

0 Matt Sunna over 4 years ago

TI__Guru* 77343 points

Hi Tang,

From your description, your connections are correct. I am not sure why the communication is not working. You might find this app note on SMBus useful for debugging, especially the section on Page 10 that covers the most common problems: http://www.ti.com/lit/pdf/slua475

If you have an EV2400 and BQStudio, you can capture the SMBus transactions on a logic analyzer to compare it to your MCU transactions to see what is different.

Best regards,

Matt

0 Tang Vy over 4 years ago in reply to Matt Sunna

Prodigy 40 points

Hi Matt,

This is my fault for posting a question on 2 different threads but I have deleted the other before. Can you give me the answer on this thread?

Thank you.

0 Matt Sunna over 4 years ago in reply to Tang Vy

TI__Guru* 77343 points

Hi Tang,

Yes, sorry I see that the other thread is deleted now.

0 Tang Vy over 4 years ago in reply to Matt Sunna

Prodigy 40 points

Hi Matt,

Thank you for your support, but I have one more question. When I establish the smbus connection between my BQ78350 and my MCU, instead of those pins I have connected before, the remain pins of the BQ78350 should be leave disconnected or any of them should be connected to anywhere special?

Thank you,

0 Matt Sunna over 4 years ago in reply to Tang Vy

TI__Guru* 77343 points

Hi Tang,

Please refer to the device pin table in the datasheet. The other pins should be connected according to the instructions in this table. Many of these pins cannot be left floating.

Matt

0 Tang Vy over 4 years ago in reply to Matt Sunna

Prodigy 40 points

Hi Matt,

Thank you for your support, I'll try to connect those pins as the datasheet mentions and see the results.

Best regards.

Power management

Power management forum

BQ78350-R1: BQ78350-R1