Hi, Team
My customer has request for schematic review for BQ40z80, can you please help to review it?
Harson,
Please see my comments below. This is not a full review, but general comments/questions that need to be addressed for a good implementation.
1. Verify that the CHG and DSG FETs can turn off in the timeframe that is expected for protection. R20 may need to be reduced (1K minimum), and R22 may also need to be reduced (4K minimum).
2. The reverse polarity protection impelmentation is incorrect. The example in the bq40z80 RevA EVM schematic is also incorrect, and should be as below:
3. There is a cap missing between VC4 and VC5. It should be the same as all the other VCx connections.
4. I am assuming that the circuit connecte to PACK (pin 25) with the PACK+_EN input is to bring the part out of SHUTDOWN through a signal generated by something not shown on the schematic. I can not say if this wil work, as I don't know what is driving the input. This whole circuit may not be needed if waking from shutdown when the charger is attached is an acceptable way of coming out of SHUTDOWN.
5. There is no secondary protection shown in the schematic. Depending on the application, this may be desired.
Please let me know if you have any questions about my feedback, or if you have specific areas of the design you are concernced about.
