TPS53355 / equivalent circuit of VBST pin

I have passed this on to the BU for support.

hi Ryuji,

We don't have documents for VBST resister effect  but the recommended VBST resister for this part is 2ohm. if you want to see the effects by using  different Vbst resisters value, just let me know the resisters values that you would like to use and i will do  some measurements on our EVM to see the effects.  Also, please see the above pic. for  Equilvalent circuit of VBST.

Best regards

Benny Gebru

HPS

Hello Benny san,

I think that VBST resister can reduce the switching spike noise.
This resister is similar with Gate resister.
So, when I increase the VBST resister, spike noise will be reduced.
However efficiency is decreased.
And I got the recommend value as 10~24ohms from the following post.
http://e2e.ti.com/support/power_management/non-isolated_dcdc/f/196/p/372873/1311614.aspx#1311614

Our customer concern the VBST resister is not effective to specifications without efficiency.
I can find the your attached pic from the datasheet.
And this picture is block diagram.
Could you please send the equivaIent circuit witthout attached pic? 

Best Regards,
Ryuji Asaka

Just FYI, that 10 to 24 ohm BOOT resistor came from a different family of dc/dc converters.  It was not a direct recommendation for your TPS53355 circuit, just an idea of where to start.  If the product line recommends 2 ohm, I would go with that.