Setting MP9486A switching frequency

Hello,
I couldn’t understand how the frequency of MP9486A is set. The max frequency is mentioned as 1 MHz. So can I assume it’ll ramp up to this value in case a spike of 2A from a 2G GSM module (2A for 0.5 ms every 4.5ms).

So can I use 1MHz for calculating the inductor needed using this tool?

Thanks, Prithvi

Hello prithvi,

This device uses a hysteric control method which has a variable frequency. Meaning, you can not set the switching frequency to a constant value like with other controllers. It will vary depending on the ripple of the output voltage.

That tool is only good for inductors values 0.33uH to 22uH. Depending on your application with this device, it may be out of your range.

A tool that can assist you in your design process is our EV9486A-N-00A | 3.5A Switching Current Limit, 100V Wide Input Buck Converter EV Board, You can also take a look at figure 4 in the DS of the MP9486A.

Thank you,
Vinh Tran
Field Applications Engineer

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Hello Prithvi, I’m trying to use MP9486 for the same application. I’m using it to give out either 5V or 4.2V output so that I could directly/indirectly (via LDO) feed it to the 2G GSM module. I’m curious to know if you were able to achieve the stability of output against those ripple currents? Could you maybe help me as well?