Hi.
I have plugged in the following values in WEBENCH for the LM2593.
Vin(min)=9V
Vin(max)=20V
Vout=5.0V
Iout=1.0A
When opening the design I received a warning the phase margin was too low (~12.xx deg). I change the value of the output capacitor for one with a higher ESR and the phase margin improved to 56.7deg. Looking through the LM2593 data sheet for Figure 1 (Adjustable Output Voltage Versions) there is the inclusion of Cff(feed forward capacitor) which is used the when the output voltage is greater than 10V or when COUT has a very low ESR. I’m using the fixed 5.0V version and my question is have I correctly improved the phase margin, or is there a better/other way of doing this, and yes I’m a power supply novice trying to get a working design.
Thanks for your help.
Martin.