Undervoltage/Overvoltage Protection
Hi,
In topswitch Hx family datasheet is suggested to connect 4M ohm resistor to V pin for Undervoltage/Overvoltage protection, But why PI expert put two 4.64 M in series, in this case due to undervoltage threshold current is 25 uA and overvoltage threshold current is 112uA so undervoltage is programmed to (4.64+4.64) *25=232V and overvoltage to (4.64+4.64) *112=1039V.
I attached the schematic
Best Regards
Comments
Hi,
Thanks a lot
I would be grateful if some one answer my question.
Best Regards
As I said, I have passed your question on to the people in charge of the actual code for PI Expert - they will need to have a look.
Thank you kindly
Does your design require UV, OV or both? In your example, you have enabled UV and disabled OV, which is why the two 4.64M resistors are used on the V-pin.
Go to the design tree on the left of your PI Expert design and select PI Device -> UV/OV and make the appropriate selection.
Thank you for your help.
I think the circuit that PI expert suggests for both UV and OV is different from the topswitch HX datasheet.
I attached 2 photos about PI expert and datasheet. Please take a look at them.
Best Regards
The two circuit implementations you have attached are exactly the same. The only difference is RLS1 = 9.31 M for the high line design - which makes sense.
Thank you for your help
I will be passing this question to the people who oversee the PI Expert software. In the meantime, please go ahead and calculate your UV/OV resistor value based on the threshold currents from the data sheet.