bq20z95 Software Questions

Ryan,

I responded to you through e-mail.

Just to be clear, once the GasGauge Impedance Track is enabled. Do I need to enabled it again after a lost of power due to battery depletion?

--Thien

No you do not need to enable it again, the gauge will remember the previous setting before a reset or POR. 

I have the Sanyo UR18650U cells. When I enable the charging & discharging FETs (via SBS command 0x46) of the GasGauge it lasted for a minute or so and the firmware may have switch the FETs off. What is the minimal effort to get set FETs on without the Gas Gauge firmware turns them off?

FYI, I don't have the golden image to program the GasGauge yet.

Thanks,

--Thien

If the gauge turned the FETs off, there may be a fault somewhere. If you can provide the SBS screen capture we can take a look and try to determine why the FETs were turned off.

Regards,

Viktoriya

That's what I suspect. Unfortunately, we're not in the EVM setup anymore. I guess I'll hardwire the I2C lines and do a screen capture that way later.

--Thien

Is there any way to get the e-mail that chase sent or the answers to those questions?

I image that other people may come through with the same problem and it would be nice to see the answers to the problems.

I'd also just like to know the answers for when I get to that stage.

We are not supposed to post the key publicly. If you would like to have it, please provide your email address or we can send it to you in a private message.

Regards,

Viktoriya

QUESTIONS:

1) How do you turn off ImpedanceTracking once you have it turn on? I turned it on but don't know how to disable it.

2) In the case, battery cells was disconnected from GasGauge. The Gas Gauge chip went to sleep. What is the "proper way" wake it up when battery is reconnected again? (I tried I2C commands but find NACK for the address 0x16 & 0x17. I tried to create a jumper across CHG_FET & DSG_FET, and that worked, but the solution is not practical.)

--Thien

1)  You can change "Update Status" to 0 or 02, follow by a reset command (0x41 to MAC) .

Update Status = 0: this is the default setting from the factory, when the DF parameters are not setup, Qmax/Ra are not updated

Update Status = 2: this is setting in a golden image DFI

2)  The battery cells should not be disconnected in normal application. In this case, the part will not be asleep but it will be powered off.

You can refer to section 2.6 Device Operating Mode in the TRM for details on sleep mode and battery pack removed mode:

http://focus.ti.com/general/docs/lit/getliterature.tsp?literatureNumber=sluu264a&fileType=pdf

Regards,

Viktoriya

Thanks Viktoriya, that works out great!

More Questions:

Can BQ20Z95 chip on its own set [FAS] flag & set [SS] flag? Is there any condition that can push it into that mode? (I was testing putting the chip into sleep & wake it up out of sleep, but after maybe ~50 runs I noticed the two flags set on me. I checked the code, and it doesn't have any Seal algorithm. I know this for certain because I attached an I2C Sniffer on the Bus)

No the chip cannot set the flags on its own but if it was previously sealed, a firmware reset may have occured and that would seal it back up.

Regards,

Viktoriya

THIS JUST HAPPENED TO ME using the bq20z45.  I left the system in the oven over the weekend for a burn-in test.  When I came back FAS and SS were set.  Did you have any luck figuring out what happened to your chip?

Regards

Ed K