Matt Sunna said:

Hi,

Please send a copy of your board schematic and your device settings. It sounds like your protection FETs might be opening whenever you connect the load. Is the load beyond the range of your fault condition settings? Make sure you have configured your protections correctly before applying the load.

Best regards,

Matt

i am getting no voltage at bq76920 Regout pin, and i am also unable to connect my board with bqstudio. i am using MCP2221 to connect my board with computer.

Hello Matt,

I tested all the voltage across all the pins, there is one thing. i am not getting any voltage at REGOUT pin of bq76920 while, REGSRG pin is getting supply.

please help me in running this design.

Hello Matt,

we checked voltage across pins you mentioned. except cap1, we got correct voltage on all power pins. but on cap1 pin there was no voltage.

please guide us in running this circuit.

Since there is no voltage on CAP1, one of the power pins for the device is not getting power. Can you send your schematic and I can help you figure out what is wrong? The schematic you sent before was from the BQ78350-R1 datasheet.

This new video may be helpful to figure out what is not connected correctly: https://training.ti.com/how-create-schematic-bq76920-bq76930-and-bq76940

Best regards,

Matt

We are using same design given in bq78350-r1 datasheet. i watched the video and it says to connect NC pins with Cap pin. while in Datasheet NC pin is left open, so we left it open too.     should we place a wire between NC pin and cap pin ?

This NC pin on the BQ76920 should not connect to anything, so you do not need to place a wire. There are NC pins on the BQ76930 and BQ76940 that have instructions in the datasheet pin table for connections to CAP pins.

If your schematic is the same as the datasheet, the device should power up correctly. In order to help further debug, we would really need to see your schematic. Also, let me know how you are applying power to the board - whether individual battery cells are connected or if you are using a power supply.

Regards,

Matt

Hello Matt,

Please find schematic in attachments.schematic design 2.pdf

schematic design.pdf

Thanks for sending the schematic. I will check for issue. Can you also tell me how you are applying power to the board? Are you connecting battery cells or a power supply and at what point are you making the connections?

Thanks,

Matt

Okay, I see an issue. The TS1 pin needs a rising voltage to bring the device out of Ship mode. See section 10.4 of the datasheet BQ76920 datasheet. Also see this app note for ways to control this pin for booting up the device: www.ti.com/.../slua769.pdf

i am powering it by connecting to battery cells.

Hi matt,

i gave rising pulse to TS1 pin and i got voltage at REGOUT Pin, still i am unable to run load. and LEDs across bq78350 are not glowing up to show soc.

There is no ouput voltage at CHG and DSG pins. They should show some voltage to drive mosfets, but they are not.

Hi,

Glad to see the device is booting up. Have you programmed the BQ78350-R1 already? The data flash needs to be programmed with information about your battery and application. The FETs are disabled until you enable them in the data flash. Please refer to this app note (http://www.ti.com/lit/pdf/slua924) and the BQ78350-R1 Technical Reference Manual (http://www.ti.com/lit/pdf/sluubd3).

If you have already set up the BQ78350-R1 and are still having trouble, please send me your data flash settings and I can help debug the issue. You can export the data flash by clicking the 'Export' button on the Data Memory screen of BQStudio.

Best regards,

Matt

Hi,

Thanks a lot for your help. We have not programmed it yet because EV2400/2300 modules are not easily available here, can you please suggest some alternative to program bq78350.

Hi Matt,

 can we use THUMBUS2300 HPA467 board or not in place of EV2300/2400?