MP9488 for 12V output

DC-DC Power Converters
1

Hello experts
We’re using MP9488 for our Battery Management System where we have an input voltage range of 10V to 150V and the output voltage needed is 12V fixed.
For this output voltage I would like to know what are the values of the associated components that might be suitable especially the R1, R2 and inductor values for 12V output and 250mA output current.

Thanks & Regards
Ibrahim Saqib

1 Like
2

You will need to use the buck-boost schematic as sometimes Vout is higher than Vin.
Unfortunately in the buck-boost topology the required switch current is Iin + Iout

So in your case a little over 500mA at 10V in. The worst case low peak current in the switch is 500mA so the MP9488 will not be able to satisfy your requirement over the entire Vin range at the load you have specified. If your actual load is 100mA then it will work

3

Got it. Our output current requirement is less than 100mA, so this should be suitable as you said.

Regarding my other doubt, what will be the values of the Resistors R1 & R2 to set the output voltage at 12V?

Thanks for the help.

Regards
Ibrahim

4

Hi Ibrahim,
You may test any a combination of dividers to get it at 2.55V for the Voltage feedback. Note for R2, it is recommended to not use higher resistor values rather values in the (4k-10k range) per datasheet.

You may try the following combination: R1 of 24k and R2 of 5.1k. This is ideal and does not account for ESR of neighboring components.

Regards,
Nouman