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LMZ14201H: Need to Internal MOSFET Characteristics

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Replies: 5

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Hello

I'm Louis Han.

Can you know Internal MOSFET Characteristics?

1. Absolute Maximum Ratings

2. ​Recommended(Continuous) Ratings​​

​​3. difference in Internal MOSFET between LMZ14201H and LMZ14202H

Can you tell me Please?

This is -7V Convertor Circuit.

1.  Input Voltage

2. Output Voltage

3. Output Current

Can you Check the Circuit and the inrush Current?

sometimes Damage occurs when power is on.

Regards.

  • Hi Louis,

    For the LMZ14201H, the absolute maximum rating for Vin is 43.5V. The recommended operating condition for Vin is between 6V-42V. The module itself is set to have a maximum current limit of 2.7A. The difference between the LMZ14201H and LMZ14202H is the trimmed current limit of the module. Nothing else is different between the two modules. 

    Regarding the waveform, is the system loaded during screen capture? Normally when the device turns on and is loaded, the output current should have the same ramping characteristics as the output voltage.

    Regards,

    Jimmy 

  • In reply to Jimmy Hua:

    Hi Jimmy

    Thanks for your support.

    This is the screen captured at system load.

    Can you give me the waveform of Normally operate?

    Is device occure damage from inrush current?

    How much maximum value the Output capacitor?

    Regards.

  • In reply to Louis Han15:

    Hi Louis,

    I want to confirm that C101 soft start capacitor is 0.0047uF. This should result in a 0.5ms soft start duration and should have reduced inrush current from the input supply since the output voltage slowly ramps to the desired output voltage. In a typical application, the minimum output capacitor follows Equation 19 of the datasheet. For reference the EVM for the LMZ14201 has 420uF of output capacitance.

    Regards,
    Jimmy
  • In reply to Jimmy Hua:

    Hi Jimmy

    Does not have Device maximum output capacitor value?

    Can you check the Output Current when uses negative output?

    Damage occurs only when the my customer uses this product as negative output.

    Can you tell me what you need to be check point when uses nagative output?

    Regards.

  • In reply to Louis Han15:

    Hi Louis,

    Generally when using a device in an inverting buck boost(IBB) topology, it is best to look out for the input voltage range and output current. In an IBB topology, the expected output current will be lower than in the regular buck topology. The input voltage range will be lowered since the reference is now negative Vout instead of ground. 

    The SLVA514B app note helps illustrate the necessary considerations when configuring a buck converter into an IBB topology. There are also wave forms that you would expect to see for startup and shutdown in this configuration. As for the inrush current spike that results from initial startup, it is still hard to determine where that is coming from. 

    Regards,

    Jimmy Hua

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