BQ51050B: NTC calculation, unable to find solution

Phillip Crosby

Part Number: BQ51050B
Other Parts Discussed in Thread: BQ51013, BQ25120A

I am using the BQ51050B to charge a battery and trying to find a solution for the NTC enable/disable function.

My limits are 0C-40C. Using the NTC tool I can not find a reasonable solution with a NTC resistor and the combination of R1 and R3.

Has anyone found a solution that will disable charging below 0C and above 40C?

over 4 years ago

0 Anthony P Pham over 4 years ago

TI__Mastermind 23410 points

Hi Phillip,

Do you have information on the NTC resistor you are using? I can take a look into this and get back to you on my results for the resistor combinations.

Best Regards,

Anthony Pham

0 Phillip Crosby over 4 years ago in reply to Anthony P Pham

Prodigy 40 points

Currently I am using a 10kohm 3435K beta NTC, and have not been able to find a solution with that value.

I am open to using another NTC, and have tried finding another value that has a solution with R1,R3 but no luck.

0 Phillip Crosby over 4 years ago in reply to Phillip Crosby

Prodigy 40 points

Anthony P Pham Any luck with finding a solution for this?

0 Anthony P Pham over 4 years ago in reply to Phillip Crosby

TI__Mastermind 23410 points

Hi Phillip,

Apologies, I will get an answer back to you soon.

Best Regards,

Anthony

0 Anthony P Pham over 4 years ago in reply to Phillip Crosby

TI__Mastermind 23410 points

Hi Phillip,

I don't believe there's a combination of resistors that allows for disabling charge outside the range 0C to 40C.

The temperature range is very small for current based temperature monitoring. The recommendation is to use a wireless receiver in combination of a charger that uses a voltage based temperature monitoring system such as the BQ51013 with the BQ25120A (an I2C charger with voltage based monitoring) or a device from the BQ2407xT family (standalone which have voltage based monitoring).

Best Regards,

Anthony Pham

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BQ51050B: NTC calculation, unable to find solution