BQ24610: Input power supply management

guy vilain

Prodigy 10 points

Part Number: BQ24610

Tool/software:

Hello,

How can I manage a multiple power supply charger of 21V or 24V with the same BG24610 configuration ?

Th target is have the same battery recharge time whatever charger.

Regards.

10 months ago

0 Christian Moyer 10 months ago

TI__Mastermind 32581 points

Hello Guy,

I'm confused on your questions. Are you asking if you can use different input adapters with varying voltages between 21V-24V?

Best Regards,

Christian.

0 guy vilain 10 months ago in reply to Christian Moyer

Prodigy 10 points

Hello Christian,

Yes , I will have same charge time with input adaptor of 21V or 24V voltages.

Regards.

0 Christian Moyer 10 months ago in reply to guy vilain

TI__Mastermind 32581 points

Hello Guy,

There should be no changes need to support both a 21V and 24V adapter.

Best Regards,

Christian

0 guy vilain 10 months ago in reply to Christian Moyer

Prodigy 10 points

That's what I thought but in reality charging times are much longer with a 24V adapter.
Charging current ICSET is set at 1.5A but with 24V adaptor , it does not exceed 700mA. Whereas with 21V adaptor , it reaches 1.5A.

Regards.

0 Christian Moyer 10 months ago in reply to guy vilain

TI__Mastermind 32581 points

Hello Guy,

Can you provide your schematic?

What is the voltage on ISET1 in both cases?

Best Regards,

Christian

0 guy vilain 10 months ago in reply to Christian Moyer

Prodigy 10 points

0 Christian Moyer 10 months ago in reply to guy vilain

TI__Mastermind 32581 points

Hello Guy,

What is the voltge on ISET1 in both cases?

Best Regards,

Christian.

0 guy vilain 10 months ago in reply to Christian Moyer

Prodigy 10 points

Hello Christian,

In both cases charge ISET1 =1.5A precharge ISET2=300mA

Regards.

0 Christian Moyer 10 months ago in reply to guy vilain

TI__Mastermind 32581 points

Hello Guy,

Can you measure the voltage on the ISET1 and Vref pin in both cases?

Best Regards,

christian

0 guy vilain 10 months ago in reply to Christian Moyer

Prodigy 10 points

Hello Christian,

Sorry I was in vaccation end of last week.

I'll check voltages tomorrow.

Best Regards.

0 guy vilain 10 months ago in reply to guy vilain

Prodigy 10 points

Hello Christian,

Measurements have been done this morning. All votages are same in both cases.

21V => Vref=3,236V and VISET1=248mV VISET2=251mV VACSET= 550mV

21V => Vref=3,233V and VISET1=248mV VISET2=251mV VACSET= 549mV

Best regards.

0 Christian Moyer 10 months ago in reply to guy vilain

TI__Mastermind 32581 points

Hello Guy,

I see no obvious issue that would cause this behavior, have you tried applying a load the system load? Can you confirm that there is not an issue with the adpater?

Best Regards,

Christian

0 guy vilain 10 months ago in reply to Christian Moyer

Prodigy 10 points

Hello Christian,

I confirm there is no issue with the adaptator.

We noticed a slight improvement by increasing the value of capacitor between SRN and SRP pins.

C13 : 100nF => 400nF.

What is the job of this capacitor and Could you confirm that this modification can be done .

Best Regards

0 Christian Moyer 10 months ago in reply to guy vilain

TI__Mastermind 32581 points

Hello Guy,

The capacitor is used for to filter differential-mode voltage to avoid amplification of high frequency signals, for more accurate current sensing.

Yes, i see no obvious issue with increasing this capacitor.

Best Regards,

Christian.

0 guy vilain 10 months ago in reply to Christian Moyer

Prodigy 10 points

Hello Christian,

I share you the SRP signal with 24V adaptor.

Green colour is SRP signal with C13=100nF

and Yellow color is SRP Signal with C13=400nF.

As you can see we have low noise with C13=400nF, but it's not perfect. Charging current is around 1.3A instead of 1.5A.

My question is : Do you have an abacus or a formula to calculate the value of L1 inductor ? Perhaps this inductor have an effect depending adaptor voltage ?