TINA/Spice/UCC256301: (simplis model) OCP on ISNS pin relevant to capacitance connected to VCC pin

Tool/software: TINA-TI or Spice Models

Hi :

Sorry to bother you.

When i try to change the OCP Threshould, i found that when the capacitance connected to VCC pin is large, UCC256301 will enter OCP fault in simplis. But when i change the VCC_capacitance to a smaller one, it will not enter OCP.

Take UCC35630x simplis model on ti.com for example. You can change R10 to 200 ohm and change C18 to 200 nF, it will enter OCP fault. But if you change C18 to 20nF and R10 to the same 200 ohm, it will not enter OCP .  But the VCC_capacitance should have noting to do with the OCP fault. Why does it happen ?

Thank you.

Best Regards,

Li, Gang