TPS53353: What does D stand for in equation 12 of the TPS53355 datasheet

Jason Waln

Prodigy 130 points

Part Number: TPS53353
Other Parts Discussed in Thread: TPS53355

In the TPS53355 datasheet Reviesed November 2016, what does D stand for in equation 12?

over 7 years ago

0 JohnTucker over 7 years ago

TI__Guru**** 191445 points

Hi Jason,

"D" is "Duty Cycle". Use D = Vout / Vin for Eq. 12.

0 Jason Waln over 7 years ago in reply to JohnTucker

Prodigy 130 points

I used Vout/Vin for D.

For Vinj_sw, I get a value of 2mV
Vin =12V, Vout =1V, R7 = 41.2K, C1= 22nF, Fsw = 500KHz

Does 2mV seem right? Doesm't seem like must of an increase in ripple at the VFB pin.

0 JohnTucker over 7 years ago in reply to Jason Waln

TI__Guru**** 191445 points

Jason,

R7 seems high. I would nee to know the rest of your design to check it. Lout Cout, Fsw, etc. Can you post or provide your design equation worksheet?

0 Jason Waln over 7 years ago in reply to JohnTucker

Prodigy 130 points

I can send you the workbench schematic/data which I don't want to post on here. How can I get it to you confidentially?

0 JohnTucker over 7 years ago in reply to Jason Waln

TI__Guru**** 191445 points

Jason,

My email is j(dash)tucker(at)ti(dot)com

Power management

Power management forum

TPS53353: What does D stand for in equation 12 of the TPS53355 datasheet