MPQ4263GQVE-0002-AEC1 Output Voltage control

DC-DC Power Converters
1

Hi,

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image690×388 41 KB

I have replicated the above schematic using MPQ4263GQVE-0002-AEC1 part number. The set current limit (CC) is 2A and Vout is set to 20 volts. The load resistance varies from 0.5ohm to 5ohm for my application.

Input voltage: 28V

The converter is working with the current limit of 2A from 5E to 2E. If the resistance is reduced from 2E down the line, at 1.5E the IC failed and stopped switching, input source went to current limit mode (though the source set current is 6A).

Could you please help in identifying the cause of failure when operating at lower load resistance below 1.5E. (at 1.5E the Vout is 3V)

Thank you for your support.

2

Hi @nuts1537 ,

The recommended maximum output power of the MPQ4263 is 140W. If your output voltage is 20V, then your maximum load would be 7A (2.85ohms) to be within the recommended parameters. We cannot guarantee operation if these maximum parameters are violated.

Thanks,
Rubas

3

We are not exceeding maximum power rating. In our application, we are using MPQ4263 for 20V/2A CV/CC application. Our load resistance varies from 0.5E to 5E.

While testing, we have achieved 2A CC control at 5E load resistance and when the load resistance is reduced from 5E down the line, still the set current was at 2A. At the load resistance of 1.5E the IC failed.

The test data is attached for your reference:

Rout Iout Vout
5E 2A 10V
4E 2A 8V
3E 2A 6V
2E 2A 4V
1.5E Failed

Could please explain the reason for failure.

Thank you for your support.

4

Hi @nuts1537 ,

Thanks for clarifying; I was under the impression that you kept Vout = 20V constant.

I have some additional questions:

  1. Can you describe your load setup? Did you use physical resistors or a DC electronic load?
  2. How did you set CC = 2A? Did you set it via MFR_CURRENT_LIMIT (D1h) register, or did use a DC electronic load?
  3. Did you modify any other registers?
  4. Can you share waveforms that show the transient when the load is changed?
  5. What is the end application for this setup?

I believe this device is mainly designed to keep a constant output voltage, not constant current, but I can double check this. The above information that I asked will be helpful for any tests that need to be done on our side.

Thanks,
Rubas