• State TI Thinks Resolved
  • Locked Locked
  • Replies 6 replies
  • Answers 2 answers
  • Subscribers 63 subscribers
  • Views 366 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.

TPS628690EVM-135: Inductor Value

Hong Jieun
Prodigy 240 points
Part Number: TPS628690EVM-135

Hi, 

I have a question about TPS628690 EVM. 

According to datasheet and EVM schemetic, when setting the Vout=0.5V, the reference value of inductor is 100nH. 

Is there any particular reason why TI recommended 100nH?

I think the 100nH value is not commonly used and manufactured by manufactures.

  • 0
    TI__Mastermind 36901 points

    Hi Hong,

    We will look into it. Get back to you soon.

    Best regards,

    Excel

  • 0
    TI__Expert 8756 points

    Hi Hong,

    TPS628690 supports lower Vouts from 0.2V to 0.8375V, hence, the inductor value is small to support lower duty cycle. Moreover, this this version of the device has been designed and validated to perform optimally with 100nH inductor. 

    You can use the below part number of the inductor from coilcraft in your design:

    If you wish to use a higher inductor of 220nH, you can use other variants of the device TPS628691 and set the output voltage to 0.5V using I2C. 

    Best regards

    Sneha 

  • 0 in reply to Sneha
    Prodigy 240 points

    Hi,

    TPS628691 also supports low voltage(0.5V), but why is it okay to use 220nH for this?

    If setting it by I2C, can the inductance be higher?

    Is it impossible to use 220nH when setting 0.5V output with TPS628690 without I2C?

    Why is the inductance different when setting the same output voltage(0.5V)?

    Best regards

  • 0 in reply to Hong Jieun
    TI__Expert 8756 points

    Hi Hong,

    TPS628690 supports even lower output voltages down to 0.2V. Hence, the recommended inductor supports the whole output voltage range instead of only one operating condition. 

    Moreover, The inductor is not related to the I2C or no I2C version. It is differentiated by the device options (depending on the output voltage it supports) as I shared in my previous post. Recommended inductor in the datasheet is to support the whole operating range of the device.

    We always recommend to follow the datasheet guidelines for choosing the passives to achieve the device's optimal performance. Hoiwever, if you wish to use a different inductor than what is proposed in the datasheet, then please verify all the relevant behaviour in your application beforehand. We will not be able to gurantee its behaviour outside of datsheet recommendations. 

    Best regards

    Sneha

  • 0 in reply to Sneha
    Prodigy 240 points

    Hi, 

    Then, even if TPS62890 and TPS628691 set the same output voltage(0.5V), do I have to choose the inductor value differently?

  • 0 in reply to Hong Jieun
    TI__Expert 8756 points

    Hi, 

    Yes, I would recommend to stick to the datasheet recommended values, so that the device guarantees its optimal behaviour across whole operating range..

    Best regards

    Sneha