Electronic load question

[ljy4468]

Hi all,
I measured boost converter with kikusui electronic load.
And when I draw 2A with elec. load, my dcdc oscillates.

But when I draw 2A with resistor (real resistor), my converter operates stable.

Then what is the difference between electronic load and real resistor?
of course, IN/OUT condition and load current condition is same.

Thanks in advance.

 

[D.A.(Tony)Stewart]

It seems you do not have enough gain margin/phase in your DC converter.

Are you using remote sensing in CR mode on the active load?

The stability of your converter can also be observed with a step load. Show some photos of layout and responses.
What is the ESR of your load capacitance and drivers and coil?

 

[chuckey]

Try putting a capacitor across your resistive load to see if the DCDC starts to oscillate. It is likely that the electronic load has one. So the real question is how likely is it that your DCDC has to operate into a capacitive load, remembering that most electronic circuits have Vcc decoupling.
Frank

 

[FvM]

Apart from expectable non-ideal behaviour of the electronic load (e.g. parallel capacitance), a current source (ideally infinite resistance) is clearly different from a resistive load.

It's well possible that the DC/DC is stable with resistive load and unstable with current source load.