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TPS61099: WeBench does not work

Kazuhiko Hirano
Genius 11563 points
Part Number: TPS61099
Other Parts Discussed in Thread: TPS61094, TPS61021A, TPS61023

Hello,

I search a boost convertor at TI.com based on the following requirements.
 Vin= 3.3V
 Vout=3.9V
 Iout(max)=0.5V
Then TI.com showed total 89 devices.
I selected TPS61099 from them and tried WeBench simulation.
However, WeBench simulation result is not available as follows.

What on earth is wrong?

Best regards,

K.Hirano

  • 0
    TI__Expert 3320 points

    Hi Kazuhiko-san,

    Currently current limit value is set to 0.8A (from datasheet) for TPS61099 in Webench.

    For your input case, the current limit is getting violated on Webench. Hence the failure. If you decrease the Iout little bit (0.4A), design should get created. I went ahead and created the 0.4 A design (below link) for your immediate reference. 

    https://webench.ti.com/appinfo/webench/scripts/SDP.cgi?ID=3B540D17998A97D1

    Kind Regards

    Bhushan 

     

  • 0 in reply to Bhushan Waghmare
    TI__Genius 11563 points

    Bhushan,

    Thank you for your response.
    Do you mean Iout + ILpp/2 could exceed 0.8A when Iout(max) = 0.5A?
    By using larger L value, customers can use TPS61099?
    WeBench does not support simulation using larger L at Vin=3.3, Vout=3.9V and Iout(max)=0.5A?

    Best regards,

    K.Hirano

  • 0 in reply to Kazuhiko Hirano
    TI__Genius 9046 points

    Hi Kazuhiko-san,

    For 3.3Vin to 3.9Vout/0.5A, assume 90% efficiency, the maximum input average current is about 0.65A. I would not recommend you use TPS61099 as the inductor ripple current does not change with changed inductance. For 3.3Vout it has 300mA ripple, which means for 0.65A Iin the peak inductor current would reach to 0.65+0.3/2=0.8A, which just reaches to minimum value of current limit. 

    The drawback of this is the transient performance when load up is worse as there is not current margin for TPS61099 to charge up Vout.

    For your case, TPS61021A, TPS61023, TPS61094 are all good devices to use. There are also other devices to be used you can always reach to me here if you have any further questions. Thanks!

    -Wenhao

  • 0 in reply to Wenhao Wu
    TI__Genius 11563 points

    Wenhao,

    I see, thank you for your detailed explanations.

    Best regards,

    K.Hirano