bq24160 / Charge stopping

S.Satoshi

Other Parts Discussed in Thread: BQ24160EVM-721, BQ24160, BQ24168

Hi,

Our customer is evaluating BQ24160EVM-721 and then they found charge stopping problem. As you can see in attached, the charging was stopped suddenly and the battery started discharged. This can be seen after start-up immediately so it does not seem to work thermal shutdown.

Please refer the attached and give your comments.

Best Regards,

Sonoki / Japan Disty

BQ24160EVM-721 charge stopped.pdf

over 11 years ago

0 Jeff F over 11 years ago

TI__Guru**** 169736 points

I am sorry but I do not have enough information. The IC has gone into supplement mode for some reason. Can the customer add the SYS voltage and current to the scope plot and zoom in so we can see what happens when at that moment?

0 S.Satoshi over 11 years ago in reply to Jeff F

Guru 21685 points

Hi Jeff-san,

Thank you for your comments. I'll request our customer to take Vsys and Isys as additional information. I'll get back to you soon.

Best Regards,

Sonoki

0 S.Satoshi over 11 years ago in reply to S.Satoshi

Guru 21685 points

Hi Jeff-san,

Please check the additional waveform as attached. Can you find any problem from these waveform?

Best Regards,

Sonoki

BQ24160EVM-721 Iin, Isys, Ibat.pdf

0 Jeff F over 11 years ago in reply to S.Satoshi

TI__Guru**** 169736 points

I do not see the cause from this waveform. The IC should not stop providing at least some current to SYS unless it is placed into HiZ mode. Is the watchdog timer expiring? Is the input adapter collapsing or is the EVM being powered by a power supply?

0 S.Satoshi over 11 years ago in reply to Jeff F

Guru 21685 points

Hi Jeff-san,

Thank you for your comments.

Today I received bq24160EVM and so confirmed what they asked. Then I concluded that this issue is happened due to watchdog timer expired as you commented. I tried to find to stop or disable watchdog timer but I could not find it.

Best Regards,

Sonoki

BQ24160EVM-721 watchdog timer expired 20140205.pdf

0 Jeff F over 11 years ago in reply to S.Satoshi

TI__Guru**** 169736 points

The bq24160 requires the HOST to send the watchdog signal or the IC will return to default mode settings. The EVM GUI provides that function. If the customer does want the watchdog in the final application, they will need to change to the bq24168.

0 S.Satoshi over 11 years ago in reply to Jeff F

Guru 21685 points

Hi Jeff-san,

Thank you for your advice. I understand about watchdog timer function.

Best Regards,

Sonoki

0 S.Satoshi over 11 years ago in reply to S.Satoshi

Guru 21685 points

Hi Jeff-san,

Let me start to discuss again about this tread. I could duplicate the charge stopping by using bq24160EVM. I set the electrical load to 4A and then increased input voltage. At the result the the charging was stopped (input current limit was reduced) at approx. Vin=7V. Can you try this on your bench and give your comments?

Best Regards,

Sonoki / Japan Disty

bq24160 abnormal charge stop.pdf

0 Jeff F over 11 years ago in reply to S.Satoshi

TI__Guru**** 169736 points

I do not understand your test setup. Where is the 4A electronic load connected? The bq24160 maximum output on SYS is 3A. What is the battery voltage? What are the I2C settings?

0 S.Satoshi over 11 years ago in reply to Jeff F

Guru 21685 points

Hi Jeff-san,

- Electronic load is connected to SYS output

- Vbat is around 3.5V, please see Vbat in attached file in previous post

- Resisters are set via GUI, please see P4 in attached file in previous post

As you commented, I understand that the load current was exceeded the maximum output on SYS output with my test condition. Then does bq24160 reduce input current limit setting when load on SYS output will be exceeded 3A?

Best Regards,

Sonoki

0 Jeff F over 11 years ago in reply to S.Satoshi

TI__Guru**** 169736 points

No but there is a cycle by cycle current limit (4.1min-5.6max) that will reduce the maximum input current. Regardless, the charging current will be reduced to zero and most likely you will be in supplement mode with the battery helping to support the large SYS load.

0 S.Satoshi over 11 years ago in reply to Jeff F

Guru 21685 points

Hi Jeff-san,

I overlooked the Cycle-by-cycle current limit.

I understand that the Isys will be increased when the Vin will be increased under input current limit worked, with the result, Isys will be hit the cycle-by-cycle current limit threshold.

Is my understanding correct?

Best Regards,

Sonoki

0 Jeff F over 11 years ago in reply to S.Satoshi

TI__Guru**** 169736 points

As VIN goes up the required IIN for for load on SYS should go down. But, if IIN gets close to the cycle by cycle limit, the IC will turn off the buck power FET before it normally would, resulting in lower duty cycle and therefore lower SYS output voltage/power.

0 S.Satoshi over 11 years ago in reply to Jeff F

Guru 21685 points

Hi Jeff-san,

I confirmed the cycle-by-cycle current limit on my bench as attached. Thank you again for your advice.

Best Regards,

Sonoki

bq24160 inductor current.pdf

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bq24160 / Charge stopping