Using less temperature sensors on BQ78PL114 than the actual number of cell

Mathieu Lafrance

Other Parts Discussed in Thread: BQ76PL102, BQ78PL114, BQWIZARD, BQ78PL116

Hi,

The title says it all, i'm trying to use BQ78PL114 along with BQ76PL102 for a total of 5 cells. I want to use a single temperature sensor for all the cells.

Do I need to do anything special to the un-used temperature sensor ? Do I short both pins ? Do I leave them open ?

I'm a little worried that the sensor might read a very high or very low temperature because it is left open. Or it might pickup noise and read incorrectly.

What are your advices ?

Thank you

over 14 years ago

0 Jim M15252 over 14 years ago

TI__Intellectual 1940 points

Unused sensors are left open circuit - no problems.

Use the bqWizard 3.0.16 to upgrade your firmware to bq78PL114S12 or use the new bq78PL116.

Then use the Pack Configuration Utility in the bqWizard to create a .tmap file which will specify how your temperature sensors are arranged.

0 Mathieu Lafrance over 14 years ago in reply to Jim M15252

Intellectual 365 points

Very useful.

Can I use the .tmap generated by BQWizard 3.0 and then use it with a BQ78PL114 with FW 4452 ?

I still have some devices that are not running FW5000 that should be modified to single temperature sensor. I do not want to convert them to FW5000 at the moment.

0 Jim M15252 over 14 years ago in reply to Mathieu Lafrance

TI__Intellectual 1940 points

You cannot use a FW5000 .tmap with FW4452.

I strongly recommend moving to bq78PL114S12. If you are using the EVM for development there is a simple upgrade procedure. All that is needed in terms of hardware is a soldering iron and some solder.

Power management

Power management forum

Using less temperature sensors on BQ78PL114 than the actual number of cell