ADP1853 power-up simPE model

Hi,

Attached is the ADP1853 Simplis model set up for start-up simulation.

Best Regards,

Hong

Hello.

Thank you for your sim data.

Immediately, I tried the simulation.

My customer's request current is 2A~10A, it changed the load.

The result is an attached graph.

However, because at light load there was ringing. I tried to optimization.

My customer request is Vin=12V~3.3V Vout=1.2V,Iout=2A~10A.

I tried to optimize in this condition.

Finally, I introduced the circuit conditions from ADIsimPow.

Ringing was suppressed by the phase compensation of the entire circuit.

Soft-start was a result of similar calculation values.

But I have a question, that Why flat Voltage output appears, is it dependent on the input voltage ?

Best Regards,

Hi Osamu,

Thanks for testing for the simulation model. The ADP1853 is one of the parts whose actual start up behavior is really hard to model, e.g. the internal comp voltage clamp level changes during startup. That’s why there is no Start-Up simulation option built in the ADP1853 design tool. Whether Vout ramps up monotonically or has a “flat voltage” during start up depends on many factors:  Cout, load, input/output voltage and so on, and usually it won’t affect the application as long as the design is stable.

It is good to order an Evaluation board to test if you want to know your actual design startup performance. Probing the voltage on the SS and Comp pin as well when you are doing the test helps you get a better insight on soft start of the this part.

Best regards,

Hong

Hi Hong.

Thank you  for your answer.

I'll make sure in the evaluation board.

Best regard.