BQ25792: NTC Function on TS Pin for BQ25792RQMR and Compatible Fuel Gauge Recommendation for 4S Battery

Akin Raj

Part Number: BQ25792
Other Parts Discussed in Thread: BQ40Z50-R2, BQ40Z80, BQ40Z50

Tool/software:

Hi,

I’m working with the BQ25792RQMR battery charger IC, and in my application, I do not require the NTC (temperature sensing) function for battery temperature monitoring. I would like to know:

How can I disable the NTC function on the TS pin?
- Should I connect the TS pin to REGN or GND directly if not using the NTC feature?
- Or is there a recommended resistor configuration to safely disable or bypass this function?
Additionally, could you please recommend a suitable fuel gauge IC that is compatible with this charger and supports a 4-cell (4S) Li-Ion battery pack?

Appreciate your guidance. Please respond at your earliest convenience.

4 months ago

0 Jeff F 4 months ago

TI__Guru**** 166106 points

Hi Raj,

Regarding 1, you can hardware disable TS by placing equal sized resistors for the resistor divider in order to set V(TS) close to 50% of VREGN. To software disable, there is a TS ignore bit.

Regarding 2, I will move this post to the gauge team to help with this.

Regards,

Jeff

0 Akin Raj 4 months ago in reply to Jeff F

Prodigy 120 points

Hi Jeff,

Thankyou for your fast response. So by placing a 10k R1,R2 divider will be good enough right?

Best Regards
Akin

0 Akin Raj 4 months ago in reply to Akin Raj

Prodigy 120 points

Hi jeff,

Could you please share some reference design files of this IC.

Best Regards
Akin

0 Alan Frias 4 months ago in reply to Akin Raj

TI__Mastermind 25565 points

Hello Akin,

A suitable gauge for a 4 cell in series battery pack would be top pick 41z90 for the highest accuracy that has the EVM and sample available but you could also go with the current generation battery gauge such as the BQ40z50-r2 or the BQ40z80.

Thank you,
Alan

0 Akin Raj 4 months ago in reply to Alan Frias

Prodigy 120 points

Hi Alan,

Thankyou for the details , could you please share reference schematic of BQ40z50-r2 in 4s configuration.

0 Akin Raj 4 months ago in reply to Alan Frias

Prodigy 120 points

Hi Alan,

Kindly share a 4s fuel gauge IC without a BMS integrated. BQ40z50-r2 or the BQ40z80 are having BMS integrated , in our case the battery pack already have a BMS and we are also not using the NTC. Please suggest a suitable active part with reference schematic or design files at your earliest convenience.

Best regards
Akin