LM5163: Low current efficiency calculations in quickstart design tool

Jason Bens1

Part Number: LM5163

I'm using the LM5163 for a low current application, around 50 mA. When I enter this into the quickstart design tool, the text in the cell goes red. The efficiency is also a lot less than what's shown in the datasheet, despite tweaking some of the other values that would affect this. I haven't simulated this, yet, to see if the Spice model shows similar behaviour. Does the quickstart calculator only model the non-DEM mode?

over 3 years ago

0 Orlando Murray over 3 years ago

TI__Mastermind 22299 points

Hi Jason,

Yes you are correct, the LM5163 Quickstart tool suggests designs for Continuous conduction and recommends large inductor based on that.

You can do this design with inductor ripple current ~100-200mA, it's just that the output voltage ripple calculation will be incorrect, as the ripple current increases you will need more output capacitance to keep the output ripple voltage controlled.

The spice models work with DEM and should model everything correctly here.

-Orlando

0 Jason Bens1 over 3 years ago in reply to Orlando Murray

Prodigy 20 points

Sounds good. Thanks.

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LM5163: Low current efficiency calculations in quickstart design tool