BQ76PL455A: Cannot get BQ to respond is it a timing issue with the packets?

Hi Anner,

Can you please clarify if you are using custom software driver or are you using the GUI or example code to send the packets? Is the schematic the same as the EVM reference or what changes have you made?

Regards,

Taylor

I am using the Customer Sample Source Code I also tried using the GUI application and the FTDI to send the packets.
The schematic changes we have made on the side of the BQ of the isolated circuit are minor how can I provide a copy of the schematic on a secure manner for you to see them?

Hi Anner,

Please friend request me through E2E and then we can privately message about this. 

Thanks,

Taylor

Hello,

Send oyu the schematic few days back was wondering if you had a chance to take a look at them.

Hi Anner,

Yes it looks like you changed the wakeup circuit, can you ensure the device is waking up by measuring the below after the wakeup command? How are you supplying VIO? Is this coming up before you start communicating?

If so please measure all of your values for the below rails:

VP = 

V5VAO = 

VDIG = 

VM = 

VREF = 

BAT16 = 

Thanks,

Taylor

What changes can you see on the schematic on the wakeup circuitry we just looked at the EVM design again and it looks the same.
I also went ahead and connected the FTDI USB from the EVM directly to the BQ side of the isolators and I can see VIO having 4.8v along with bat16 having 32v 
Forgot to measure the other rails will do so later.

Hi Anner,

Are you still having problems?

If yes then please provide data Taylor requested earlier.

4.8V sounds too low.

I am specially interested in VIO.

roger 

Apologize been travelling,

Went ahead and measured the rails.
Why would the VM be so low? in the EVM it reports -5.191 instead of -0.076