MP4581 maximum duty cycle

MP4581 datasheet feature list mentions 90% Maximum Operation Duty Cycle. In the Electrical Characteristics table I cannot find any information about max/min duty cycle. Is the 90% maximum a hard limit ?

Hi Mario.

Typically I use a combination of Fsw and min off time to calculate the maximum duty cycle. For this part it would initially seem as if with 100kHz Fsw and 150ns min off time that you could switch with a 98.5% duty cycle, but as you said the datasheet says to remain within ~90%.

This is because at a higher duty cycle, say 98%, we have to rely on a relatively weak BST voltage around 3V, and we’re better off at steady state staying within 90%.

As a note, I wouldn’t recommend switching as slow as 100kHz anyway since we will require larger inductance and higher peak currents.

When will the MP4581 be available from distributors?

Hi dcarrington, welcome to the forum and apologies for the delay in response.

The MP4581 can be ordered by distributors now.