BQ27530EVM: Data flash writing fails at verifying if battery isn't connected.

Alexandru Petrescu

Part Number: BQ27530EVM
Other Parts Discussed in Thread: BQSTUDIO, , EV2400

Hello,

I'm trying to update the data flash but without a battery connected. It fails at verify ( see attached print screens ). The gauge is powered at J1 connector. Tested with various voltages ( 5V, 7V, 9V ) but no success. This isn't supported by this gauge?

Regards,

Alexandru Petrescu

over 5 years ago

0 Kang Kang over 5 years ago

TI__Mastermind 24870 points

Hello Alexandru,

Make sure you are not hitting current compliance. Flash programming needs to be above 2.8 volts by default and you will need to compute the right checksum values.

0 Alexandru Petrescu over 5 years ago in reply to Kang Kang

Prodigy 250 points

Hello Kang,

The Vcc of the gauge is rock solid at 2.5V. I sampled it with an oscilloscope. So, these can't be the problem. And the CRC is computed by the bqStudio program. Take a look at the attached print screens. I've used the tab where I can modify the data flash without worrying about computing CRC. And the same data flash write operation is successful if I connect a battery. The rest of the system remains unchanged. So, which is the problem? Why writing in the data flash isn't possible if a battery isn't attached? I haven't seen any information on the datasheet about this behavior.

Regards,

Alexandru Petrescu

0 Alexandru Petrescu over 5 years ago in reply to Kang Kang

Prodigy 250 points

Hello Kang,

Did you managed to reproduce the issue?

Regards,

Alexandru Petrescu

0 Kang Kang over 5 years ago in reply to Alexandru Petrescu

TI__Mastermind 24870 points

Hello Alexandru,

From screenshot, you are not in FAS mode. Make sure to send both the unseal keys and the full access keys to unlock the gauge for DF write.

0 Alexandru Petrescu over 5 years ago in reply to Kang Kang

Prodigy 250 points

Hello Kang,

According to the TRM, FAS mode is only used when the keys are to be changed. I didn't tried to change the access keys so no need to put de gauge in FAS mode. But anyway, I just performed a test with gauge in FAS mode and without battery connected, the DF can't be updated. Got any other explanation of why the gauge ignores DF write? I mean, I did managed to update almost everything on the gauge ( sleep, hibernate, read FW version, charge enable, unseal, even read the DF without problems ) except DF writes when the battery pack is not connected. I can think of a reason of why is forbidden to write without battery but I need an official one from you, the manufacturer.

Regards,

Alexandru Petrescu

0 Kang Kang over 5 years ago in reply to Alexandru Petrescu

TI__Mastermind 24870 points

Hello Alexandru,

Please place the gauge in FAS mode and try to write DF. I believe that is the issue here.

0 Alexandru Petrescu over 5 years ago in reply to Kang Kang

Prodigy 250 points

Hello,

As I said in my previous post, I already tried to write the DF with gauge in FAS mode. It doesn't work. Any other ideas?

Regards,

Alexandru Petrescu

0 Kang Kang over 5 years ago in reply to Alexandru Petrescu

TI__Mastermind 24870 points

Hello Alexandru,

Please send me a screenshot of what failure you are getting. I'm looking for the red text on the corner of bqStudio when you try to change DF parameters. I'm wondering if you are hitting a min threshold of the bqz file.

0 Alexandru Petrescu over 5 years ago in reply to Kang Kang

Prodigy 250 points

Hello Kang,

OK. So the print screen and my detailed explanation is not enough. Here, I've prepared a video:

www.dropbox.com/.../IMG_2392.MOV

I'm sure it is crystal clear now.

Regards,

Alexandru Petrescu

0 Kang Kang over 5 years ago in reply to Alexandru Petrescu

TI__Mastermind 24870 points

Hello Alexandru,

The video was helpful. You need to hit write all before hitting read all again.

0 Alexandru Petrescu over 5 years ago in reply to Kang Kang

Prodigy 250 points

I've used write all and it doesn't work. See below print screen with error code.

0 Alexandru Petrescu over 5 years ago in reply to Alexandru Petrescu

Prodigy 250 points

And I was expecting not to work because if you would have paid attention to the video, the only difference between working and not working is the presence of the battery. Any other lame explanations? I have all year.

0 Kang Kang over 5 years ago in reply to Alexandru Petrescu

TI__Mastermind 24870 points

Hello Alexandru,

It seems that the CC Delta parameter on the bqz is the issue here. Yet that is in the calibration section. Are you changing that parameter at all?

0 Alexandru Petrescu over 5 years ago in reply to Kang Kang

Prodigy 250 points

Hello Kang,

No, I didn't modified the CC Delta parameter. It seems that the bqStudio has a bug. I'm using the latest version (1.3.86). It is easy to reproduce it: just use a BQ27530EVM and without battery connected, open the "Data Memory" tab. Wait for a couple of seconds while the program reads all the DF and then just hit "Write_All". Anyway, I've used an I2C bus analyzer to spy on the communication between EVM and EV2400 and I can assure you that if you modify a field in the bqStudio, Data Memory tab and press enter, then bqStudio sends all the page which includes the modification to the EVM. So, no need to hit "Write_All".

Considering what I've said above, I ask one more time: the DF can be updated without a battery being connected?

Regards,

Alexandru Petrescu

0 Kang Kang over 5 years ago in reply to Alexandru Petrescu

TI__Mastermind 24870 points

Hello Alexandru,

DF can be updated without system interaction, but without a battery connected, the device should have no power, so no updates will occur.

0 Alexandru Petrescu over 5 years ago in reply to Kang Kang

Prodigy 250 points

Hello Kang,

If by device you mean the gauge then I disagree, the gauge is very well powered if only the Vin is applied to the EVM board. I've measured the TP9 ( VCC of the gauge ) and it is 2.5V as it should be. Moreover, if there is no power how come the reads from DF are working very well without battery being connected?

Clearly, you don't have an answer to my question. Don't you have a more technical person in your organization which can provide a better answer?

Regards,

Alexandru Petrescu

0 Kang Kang over 5 years ago in reply to Alexandru Petrescu

TI__Mastermind 24870 points

Hello Alexandru,

I guess the reason I don't have an answer is because I don't really understand the issue you are facing. Can you tell me how to replicate the issue?

0 Alexandru Petrescu over 5 years ago in reply to Kang Kang

Prodigy 250 points

Hello Kang,

What about using the video sent by me last week. The video you said it was helpful. Anyway, here is what you have to do in order to reproduce the issue: take one bq27530EVM board and connect it to a PC ( with bqStudio installed ) via a EV2400 adapter. Apply voltage ( between +5V and +10V ) to J1 pin header and try to update the DF. For example, "Design capacity". Or "SOC1 Set Threshold".

Regards,

Alexandru Petrescu

0 Kang Kang over 5 years ago in reply to Alexandru Petrescu

TI__Mastermind 24870 points

Hello Alexandru,

Can you try to write it via 0x3E/0x3F instead of using bqStudio?

It is in the TRM section for writing DF.

0 Alexandru Petrescu over 5 years ago in reply to Kang Kang

Prodigy 250 points

Hello Kang,

I already tried that before I opened this thread. It doesn't work on my side. What is the situation on your side? Did you managed to reproduce the problem?

Regards,

Alexandru Petrescu

0 Dominik Hartl11 over 5 years ago in reply to Alexandru Petrescu

TI__Guru 61006 points

The gauge requires that the voltage on BAT is above Flash Update OK Voltage. It doesn't matter that the REGIN and/or VCC voltage is within spec, what counts is the voltage that the gauge measures on BAT.

0 Alexandru Petrescu over 5 years ago in reply to Dominik Hartl11

Prodigy 250 points

Hello Dominik,

Finally, I got the answer I already anticipated: flash writes are disregarded if the battery isn't connected. Most probably to secure the voltage while during flash write operations. Please add this information to the datasheet as right now only Vregin is mentioned as a condition for DF writes: > 2.8V.

Regards,

Alexandru Petrescu

0 Alexandru Petrescu over 5 years ago in reply to Alexandru Petrescu

Prodigy 250 points

Hello Dominik,

I just noticed that you are application manager. Are you aware that bq27530 is missing a TRM to this day? I have posted a request for the TRM in August last year. And speaking of documentation, the existing one is not very accurate. For example, in the documentation the "Flash Update OK Voltage" has a valid minimum value of 0( see "flash update ok voltage - datasheet.jpg" ) but the bqStudio rejects any value lower than 2700mV( see "flash update ok voltage can't be set to a value less than 2700mV.jpg" ).

Regards,

Alexandru Petrescu