Battery Babysitter - Unknow connection: BQ24075's TS pin to BQ27441's BIN

Components & Accessories Power
1

Hi,

I am looking into the Battery Babysitter and the schematics in detail.

Can someone elaborate why the BQ24075’s TS pin is connected to BQ27441’s BIN pin?

According to the datasheet it should (for removable batteries) be connected to VSS, right?

TS is for connecting “External NTC Thermistor Input” to the charger IC and BIN is for Battery Insertion Detection Input. No clue how they would cooperate.

2

Unfortunately, the original engineer isn’t available to provide clarification on this design choice. However, this might help explain some of the choice:

“If [BI_PU_EN]= 0, then the host must inform the gauge of battery insertion and removal with the BAT_INSERT andBAT_REMOVE sub commands. A 10-kΩ pull down resistor should be placed between BIN and VSS, even if this pin is unused.”

I think the TS pin was just a convenient place for the using the already existing pull down resistor.