• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 2 answers
  • Subscribers 63 subscribers
  • Views 87 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

BQ25820: Optimized duty cycle

Shachar Armon
Prodigy 230 points
Part Number: BQ25820

Tool/software:

Hi,

I would like to verify/ confirm the DCDC duty cycle

Our case:

- Lithium ion battery pack, 5S or 6S *the PCBA will be modified between this two battery pack options, required minimal BOM change, meaning FB resistors only

- Charging levels- 30W up to 70W

- External VDC input power- 36Vdc (required for others requirements)

The calculated DCDC charger D.C is  50% to the 5S option and 60% for the 6S option,

what is yours opinion?

BR

Shachar 

  • 0
    TI__Mastermind 32581 points

    Hello Shachar,

    Based on my calculation the max dutycycle for 5s should be 60% and 70% for 6s. What is the purpose for this calculation? If it is for selecting inductor/MOSFETs, I would recommend using 50% in your calculation, this is when you will see the most noise.

    Best Regards,

    Christian.

  • 0 in reply to Christian Moyer
    Prodigy 230 points

    Hi Christian,

    I can control by the design the external VDC input level, meaning to control the DCDC duty cycle by this, I wondering for what duty cycle to design for having the best EMC results and efficiency results with the BQ25820 for charging 5S or 6S with charging current up to 4A

    BR

    Shachar 

  • 0 in reply to Shachar Armon
    TI__Mastermind 32581 points

    Hello Sharchar,

    Shachar Armon said:
    I can control by the design the external VDC input level, meaning to control the DCDC duty cycle by this, I wondering for what duty cycle to design for having the best EMC results and efficiency results with the BQ25820 for charging 5S or 6S with charging current up to 4A

    I understand now. I would recommend 60-80% duty cycle.

    Best Regards,

    Christian.