MPsmart Behavior of MPM3683-7

Integrated Inductor Power Modules
1

Hi, I have a question about the simulation(at MPSmart) behavior of the MPM3683-7.

The circuit used for the simulation is shown in the diagram below.

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From the simulation results, it appears that the device behaves differently depending on the input timing of VIN and VEN.

  1. In the attached Image 1: When the EN pin is enabled at the rising edge of VIN, Vout is output normally.

    Image1
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  2. In the attached Image 2: When the EN pin is enabled after VIN has been high for a sufficient amount of time, Vout does not output.

    Image2
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Could you please explain why this difference in behavior occurs?

We suspect that this behavior might be due to the simulation model itself. If you have any evaluation results or data from actual hardware testing, could you please share that information with us?

Thank you for your support.

2

Hello Masahiro-san,

Apologies for the late response to this request.

This is interesting and seems to be just a symptom of the model.

We have similar data that shows that the EN signal dictates Vout with and without a load in hardware, but none of these waveforms actually show Vin and therefore I cannot tell when Vin is being applied here before or after the EN signals are on with respect to Vin:

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