Hi Design support,
On the joined file, you will find à WBDesign corresponding to our need.
All suggested values has been implemented on the evaluation board LM5175EVM-HD with the others adjustements below :
voltage Bias is provided by a 10V volts auxiliary supply.
Mosfet rating is changed at 60V
Add of ouput chimical capacitors 3x150µF, 180mR ESR instead of the 33µF suggested by WBDesign (necessary to provide pulsed current 10A@30µs required by the target application)
The 100µH inductor has an esr lower than 50mR.
All other WBDesign suggestions are respected
Our problem with a static load of 0.1A : At 5V input, voltage doesn't reach 50V.
It's necessary to increase the input voltage up de 6/7V to reach the 50V outpup target.
question : why it doesn't operate at 5V input voltage? Does the input/output voltage ratio too large?
After,
We tryied to decrease the switching frequency down to 100KHz, to increased the sense filtering (Ccs=1nF), to adjust the compensation with larger capacitor (Ccomp from 10 to 22nF, Rcomp from 3 to10K, Ccomp2 from 0.1 to 1nF). Nothing helps.
The better results were obtained by reducing the shunt capacitor down to 22mR ; but an instability occurs on the input current.
Hoping you can help us to find a solution,
regards,
AM
