Misleading statement about TS function of BQ25120A

[cyber_v1]

Hi,

Our development board uses BQ25120A for battery management.

In the datasheet section 10.2.2.1 Default Settings, there is a statement:

• If the function is not needed, connect TS to the center tab of the resistor divider between VIN and the ground.
(pull up resistor = 14 kΩ, pull down resistor = 14.3 kΩ)

We didn't need the TS function at this time, so we followed that advice. However, upon assembly, the charging did not work. We figured out it was because of a TS fault. Checking the datasheet again, section 9.3.16 External NTC Monitoring (TS) says: "To disable the TS function, pull TS above TSOFF threshold." Then checking the TSOFF threshold, it's minimum value is 55% of VIN, and the 14k/14.3k divider only gives around 50%. I believe these values are applicable for the case when TS function is used with a 10k NTC (b=3370), contrary to what 10.2.2.1 says. And if the function is not needed, the pull up resistor should be 10k or less. So it is either misleading, or there is a mistake in the stated pull up resistor value.

Regards

[Peter BENSCH]

Users of this forum for devices from STMicroelectronics should feel very honored that you are asking a question about devices from Texas Instruments – I'm just afraid that you won't get many answers.

Regards
/Peter

[cyber_v1]

LOL

Sorry

[Andrew Neil]

You realise that the BQ25120A is a TI (Texas Instruments) device, right?

https://www.ti.com/product/BQ25120A

For support/feedback with TI devices, you need to go to TI - it is nothing to do with ST!

https://www.ti.com/product/BQ25120A#support-training

https://www.ti.com/info/customer-support.html 

[cyber_v1]

Thanks. I guess being fever-ish doesn't help with thinking straight.

[Andrew Neil]

If you do raise this on the TI forums, please post a link here - so that anyone else who arrives here via search will be able to follow it!

 

Get well soon!