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Load fluctuation data for ADP2120

Dear Sir/Madam,

Do you have the data of the load fluctuation for ADP2120?

eg; 0.2A --->  1A curent grow up as transient.

I cant find it on your datasheet.

Only found 0A at max output on Fig.24,27, it is the load transient.

Thanks Kaos

  • Kaos,

    load transient depends on the ammount of capacitance added to the output.

    You may want to consider using the ADP2120 design tool to identify how much capacitance you will need for a specific transient requirement.

    ADP21xx Buck Regulator Design Tool

    ADP2105, ADP2106, ADP2107, ADP2108,

    ADP2109, ADP2118, ADP2119, ADP2120, ADP2138, ADP2139, ADP2164

    Best Regards,


  • LucaV, Thanks for your advice.

    But I am not clear for this.

    I did your excel design tool and got the result C3=22uF L1=2.2uH.

    So how can I bring my transient ratings?

    My info what I want to know is

    when the current make change 0.2A to 1A ,

    how the output voltage is change to drop?

    eg; condition

    input 5V

    output 3.3V

    current 0.2A (always run) but transient run 1A on sometimes

    Does the output voltage drop 3.3V to 3.0V in an instant??

    What is the instant time? 1msec? 10msec?

    Do you have the similar ratings data for this?

    I would like to refer to it.

    Thanks Kaos

  • Kaos,

    you are in control of the transient.

    Use the advanced setting function in the tool to define the maximum current step and the associated voltage transient (see images below)

    This assumes a step response with 0 transition time for the current step, the settling time cannot be adjusted as this device has internal compensation but voltage deviation will be limited to your specifications. It will probably settle in the 1ms range or less (depending on the numbers you entered for Vstep)