MPM3612: Maximum capacitance

Integrated Inductor Power Modules
1

Hi,
There is the formula in the datasheet for MPM3612:

image
I understand it this way:
The output voltage needs to be reached within tss?
I think ILim_AVG is the total current to the load and the output capacitance. So the formula ILim_AVG - Iout is the current in the output capacitor.

I am not sure how to use this formula to determine the output capacitance with a given output current?
Could somebody please advice.

Thank you.
Br. Thomas

2

Hi @thomas.sorensen ,

You are correct that ILIM_AVG - Iout is the current into the output capacitor. You may approximate ILIM_AVG with the typical low-side (LS) valley current limit.

Typical low-side (LS) valley current limit is specified as 1.4A in the datasheet.

The other variables in equation 10 are defined as follows:

  • Vout: Set by customer.
  • Iout: Set by customer.
  • tss: Fixed to 1.3ms internally.

Please note that the Cout_max calculated is an estimate, and proper functionality should be verified in circuit.

Thank you, Will

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