TPS40170: TPS40170 good choice?

Are you using one IC for all of them?
Otherwise, you can take a look at
LM73605 for 4A and 5A design
LM43601 for 1A design
All the above selection has integrated switch and compensation, therefore it is relatively easier to design than controller.

As for the 8A, seems like the TPS40170 might be ok, but i would suggest to run a webench to get a reasonable component selection and sample layout. Here is one example
webench.ti.com/.../SDP.cgi

Thanks
-Arief

Hi Arief.

Thank you for your fast replay.

I am sorry, i forgot to clarify some informations about my design.

For all my designs i need enable and pgood signal for chain power on and last power good to MCU.

My pcb will be 8 - 10 layer and 2 or 4 layer totaly ground. PCB size 210mm x 297mm

My maximum component hight can not be more than 6.3mm. No air cooling but i can use aluminium case for cooling.

By the way i can split 1.2V power rail to 2 section. 4A each.

When i try LM73605 series in webench the only problem is the inductor.


How about tps54541 series for 4A-4.5A output? 1.2V - 2.5V - 3.3V - 10V

In webench it seems the hottest part diode. I belive i can cool it with case touch.

What do you think?

Best regards.
Erman Arslan

Hi Erman,

The TPS54541 seem to be ok also. Is the inductor too large on LM73605? because normally you select an inductor that can handle at least the current limit for the part. Yes the diode will be hot especially when you are in low duty cycle condition. Webench should give you a general idea of how the thermal goes.

I would suggest try maybe running at lower frequency just to minimize switching losses and improved your efficiency especially with higher current part.

Thanks
-Arief