BQ40Z80: High Temperature after pressing DISP Button at Pin13

Klaus

Expert 1430 points

Part Number: BQ40Z80
Other Parts Discussed in Thread: BQSTUDIO

Hi Ti Experts,

we have developed a BMS with the bq40z80. It is a 7S1P Lion application.

Now I have noticed that when I press the DISP button (Pin13) continuously, a current of about 25mA flows.

This results in following thermal image:

I think that is a high temperature.

What do you suggest. Is this a critical condition?

What should we do?

I can also see the temperature in the bqStudio:

Thanks for helping us.

Klaus

over 4 years ago

0 Nick Brylski over 4 years ago

TI__Mastermind 19195 points

Hi,

Can you verify that the current is due to the LED drive. You can increase the resistance in series with LEDs.

BR,

0 Klaus over 4 years ago in reply to Nick Brylski

Expert 1430 points

Hi Nick,

thanks for your answer.

I have made the test without activate the LED_EN.

So no LED is lighting.

If I activate the LED_EN two LEDs are lighting (3,6V/cell) and the current is then around 31mA.
Therefore an LED draws about 2mA.

When I measure the current flowing through the button, it is also around 27mA.

So I think the LEDs are not the reason for the increased current consumption.

Thanks for helping us.

Klaus

0 Wyatt Keller over 4 years ago in reply to Klaus

TI__Guru** 105590 points

Hello Klaus,

Can you test with the most updated firmware and share the .gg file so we can take a look? Make sure the configuration is correct to enable the DISP functionality, pin 13 can be configured with different pull-ups that could cause higher currents like you are seeing to occur.

Sincerely,

Wyatt Keller

0 Wyatt Keller over 4 years ago in reply to Klaus

TI__Guru** 105590 points

Hello Klaus,

If you could share the .srec then we can test on our side as well.

Sincerely,

Wyatt Keller

0 Klaus over 4 years ago in reply to Wyatt Keller

Expert 1430 points

Hello Wyatt,

thanks for your answer.

I can send you the *.gg and the *.srec in a offline message.

Please accept my friend request.

Thanks.

Klaus

Power management

Power management forum

BQ40Z80: High Temperature after pressing DISP Button at Pin13