BQ25170J: BQ25170J Charger IC Selection

Nivethitha D

Part Number: BQ25170J

Hi,

We are planning to use the BQ25170J Charger IC for our Li ion cell, which has 10K NTC inbuilt in it.

When charging, the thermistor inside the battery will be connected to Charger IC TS pin and it will monitor the battery temperature.

When discharging, the same thermistor inside the battery will be connected to Microcontroller as a voltage divider circuit.

When charging, the supply connected to the controller will be disconnected using load switch. So, it will no create any voltage during charging in thermistor

Will this be okay.?

Can we connect same thermistor pin to both Controller and Charger IC?

over 2 years ago

0 Bill Johns over 2 years ago

TI__Guru* 76666 points

Hello

The current to NTC out of TS pin is very low only 38uA. Any additional load from the Microcontroller or voltage divider circuit will change NTC performance and hot / cold trip points.

Possible solution would be a switch circuit that would disconnect all circuits from the TS / NTC during charging.

0 Nivethitha D over 2 years ago in reply to Bill Johns

Intellectual 370 points

Hi,

Yes, we planned to disconnect the TS pin from microcontroller by using a mosfet circuit during charging. Will that be enough?

When charging our system will not be powered up. And during discharging the NTC will be connected to controller ADC pin

+1 Bill Johns over 2 years ago in reply to Nivethitha D

TI__Guru* 76666 points

Nivethitha D said:
Yes, we planned to disconnect the TS pin from microcontroller by using a mosfet circuit during charging. Will that be enough?

Sounds good that should work.

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BQ25170J: BQ25170J Charger IC Selection