BQ76PL455A-Q1: Hardware Problem in Evaluation board

Hi Mohit,

Thank you for reaching out to us! You are correct that the NPN should be in saturation, and in order to debug the issue further, would you be able to provide a schematic of your design?

Thanks,

Vince

The schematic file of our design is attached herewith:6724.Passive_BMS_E1.pdf

Hello,

What is voltage you are supplying on the TOP pin? And what is the current range and current clamp of your power supply (supplying TOP pin)?

Also, the transistor you mentioned at the beginning of the thread and the one on the schematic are not the same. Could you please let us know which one is the one you are using?

Best regards,

Leslie

Voltage at the TOP pin is: 52.8 V (Nominal) and the current input will be very low (will be less than the sink current od TOP pin)

We have revised the schematics and have changed the transistor ( ZXTN25100BFH, as mentioned above ) in our PCB. 

Hello,

I want to know whether you are waking up the device properly.

Do you think you can capture WAKE and VIO signals?

Roger

Yes here is where we are encountering the faults. We give 5V at the WAKE pin but the major issue is that the IC after wakeup should give 5.2V at V5VAO. But each time we test, we don't get the desired output voltage at the VIO and V5VAO pin. We have tried soldering new IC each time, but that doesn't work. Guide us further.

Hi,

Yes you are right. But while testing, each time there is a lot of heat dissipation in the resistance connected from TOP to collector point of NPN Transistor. Since the amount of current exceeds, it pulls the NPN transistor into Cutoff Region.