ST1S40 maximum inductance.

anubirux · ‎2015-07-21

Posted on July 21, 2015 at 11:07

Hello,

I design DC-DC converter using eDisign and I make it with folowing parameters:

Vin = 11-14 V

Vout = 5 V

Iout = 700 mA

Design software limits maximal inductance for this IC to 10uH, but then IL ripples are quite big ( around 50%). Can I use it bigger inductance for this IC or it's not possible ? I didnt see any information about it in data sheet.

Nickname5621_O · ‎2015-07-28

Posted on July 28, 2015 at 11:24

Hello,

the e-design is an automatic tool that allows the user to easily realize an application.

The tool is utilized to match a lot of different conditions but, to don't increase its complexity, it has been necessary to establish some conditions for the power components.

The condition you have seen on e-design is due to the implementation of the tool, not to a limitation of the device.

The official technical document of the device is the datasheet, following the equations reported it's possible define a working application with a coil value bigger than 10uH.

Following your specs:

-> Vin = 11-14 V

->Vout = 5 V

-> Iout = 700 mA

I have realized on the evaluation board of the device the attached application.

Best regards.

________________

Attachments :

Application.png : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006HzDB&d=%2Fa%2F0X0000000bIR%2FlVjVDLeFq8vhTFjOFuwPNVtywBSOBJLT16PkET7szP4&asPdf=false