BQ24172: BQ24172

Hello Chaitanya,

One more thing to try is to change the R659 and R661 to 4.02kohm, currently you have them as 40.2kohm, this is correct.

Best Regards,

Christian.

Hello Mr. Christian Moyer

I'm sorry to say this, issue not resolved, the stat pin is continuously shifting from 1.8V to 3.3V, i hope you could resolve my issue.

thanks and regards;

Chaitanya Krishna .D

Hello Christian,

No, we aren't using any thermistor, is that necessary?  even after trying your suggestion the STAT is still blinking, I'm sorry.

Thanks & regards;

Chaitanya Krishna.

Hello Chaitanya,

Can you measure the voltage on some of the pins?

REGN, OVSET, TS, ACSET, VREF.

Best Regards,

Christian.

Hello Christian,

Apologies for the late response,

REGN: 5.99V

OVSET: 1.226V

TS: 1.94V

ACSET: 0.8V

VREF: 3.3V

Thanks & Regards,

Chaitanya Krishna

Hello Christian

I forgot to mention, the adapter input was 13.5V.

Thanks & Regards,

Chaitanya Krishna 

Hello Chaitanya,

I don't see any other obvious issue with your schematic, do you see any changes if you increase your input voltage? is there a current limit on your adapter?

Best Regards,

Christian.

Hello Christian,

I tried changing the input voltages to 12V, 12.5V, 13V, 13.5V, and even 15V, but the battery still doesn't draw any current from the source. It always shows 0.00A, and the STAT pin continues to blink.

Best Regards,

Chaitanya Krishna

Hello Chaitaya,

Can you remove the battery, and apply a 1-3A load on the VCC_12?

I want to determine if the issue is related to the input source.

Best Regards,

Christian.

Hello Christian,

I've checked using different power sources, and to provide more clarity, I’ve attached some pictures of my observations. Kindly take a look when you have a moment.

Thanks and regards,
Chaitanya Krishna

Additional Pics

Hello Christian,

I'm sorry to say this, but you've already suggested this before. I tried adding a 10K parallel resistor to R671, and the problem is still the same. I don't understand why my circuit isn't functioning, despite trying multiple solutions. I’m hoping you can help clear up this issue.

Best Regards,

Chaitanya Krishna

Hello Chaitanya,

chaitanya krishna d said:

I'm sorry to say this, but you've already suggested this before. I tried adding a 10K parallel resistor to R671, and the problem is still the same. I don't understand why my circuit isn't functioning, despite trying multiple solutions. I’m hoping you can help clear up this issue.

No, the 10kohm resistor was to act as a thermistor, in some of our devices the thermistor is required. 

My thought is to change the resistor divder on the TS pin:

Please refer to Section 9.3.18 Temperature Qualification: are typical recommendation is to use a 5.23kohm and 30.1kohm.

This is typical circuit:

This is your circuit, I'm not sure how these values were chose, these values seem reaaly high.

So, I first recommend changing R669 and R671, if this does not work, add in the 10kohm resistor to act as the thermistor. Please let me know if this works.

Best Regards,

Cchristian.

Hello Christian,

Apologies for the delay. I checked the circuit using your corrections. I removed the 10K resistor in parallel with R671 (30.1K), but the stat pin still blinks. I then replaced the 10K resistor in parallel with R671 (30.1K), and R669 is 5.23K. However, the issue remains the same. I also used a 1A load. While using the load, the STAT LED glowed continuously, even when I removed the source. When the load was on the battery, the LED did not stop glowing.

I hope this information helps you with further corrections.

Thank you,
Chaitanya Krishna

Hello Chaitanya,

Can you provide an update to date schematic, to confirm all of the suggested changes?

Have you tried replacing the IC? it could have been damage previously.

chaitanya krishna d said:

I then replaced the 10K resistor in parallel with R671 (30.1K), and R669 is 5.23K.

Can you confirm that the 10k resistor is only in parallel with R671?

What is the voltage on the cell/FB pin?

Hello Christian,

The voltage at the cell/FB pin is 1.99V. I don't believe the IC is damaged because everything is working fine, and the transistors are switching as expected. However, I haven’t noticed that the battery is being charged. The STAT pin always blinks. Also, please check the attached updated schematics. And thankyou for your assistance. I hope we can solve the issue.

Best Regards,

Chaitanya Krishna

Hello Chaitanya,

I will send you a private message through email.

Best Regards,

Christian.