BQ25120: Disable or not use Temp sense resistors on the BQ25120 device.

Todd Keppler

Part Number: BQ25120

HI,

I would like to not have the temp sensor resistors on the BQ25120. We don't have a temp sensor in the battery. How do I disable this? With a dead battery, there will be no micro until it is turned on. At what point does sys turn on?

Thanks

Todd K

over 7 years ago

0 Robin Tang over 7 years ago

TI__Prodigy 670 points

If you don't have a temp sensor in the battery, you can connect a resistor at the TS pin, that not use the bq25120a temperature monitor function.

0 Todd Keppler over 7 years ago

Prodigy 180 points

Can I just short the TS pin to Vin to disable or do I need to pull it up with a resistor?

I don’t want the extra resistor if I don’t need it. Would prefer to disable to just tie it to VIN using a trace is possible.

Regards,

Todd K

Avnet

0 Robin Tang over 7 years ago in reply to Todd Keppler

TI__Prodigy 670 points

Yes, you can pull it up to TS, make sure the voltage at TS pin is higher than TSOFF(>60% VIN), that to disable the TS function.

0 Nate Enos over 7 years ago in reply to Robin Tang

TI__Genius 9430 points

Hi Robin,

So just to confirm, the resistor is not needed? You can directly short TS to Vin?

Thanks,
Nate

0 Raheem over 7 years ago in reply to Nate Enos

TI__Mastermind 21590 points

Hello Enos,
That is correct. As explained in section 9.3.16 of the datasheet, putting the voltage on TS above the TSoff threshold will disable the TS function. The TSoff threshold is between 55% to 60% of VIN so pulling TS up to VIN will disable the TS function. Shorting VIN in TS will cause a slightly higher current consumption on VIN than if you use a pullup resistor.

Regards,
Raheem

Power management

Power management forum

BQ25120: Disable or not use Temp sense resistors on the BQ25120 device.