Can I use Control pin for ON/OFF of Topswitch HX ?
Posted by: MaheshLipare
on
Hi
Can I use Control pin to make Top Switch On/OFF in my output over voltage condition. I have added one transistor which will turn on in case of output voltage is more than 130% of set voltage and pull control pin down.
I am aware I can use another pin to make it shutdown. But need your recommendation on it.
Lipare
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Thanks ! Do you have any documents to say you should not use this pin ? I want it for referance.
Sorry for that.
I guess your point is using the same optocoupler for both regulation and OVP protection. I do not like this idea, the reason is explained as follows: Becaue the feedback circuit in the secondary side not work, the ontput voltage is out of control and over voltage happen. But at the same time,you want to use the secondary side feedback circuit for your OVP protection.
For a reliable OVP protection, the protection circuit must be isolated from the feedback circuits. Since you have to use another optocoupler, you do not have to use the C pin for OVP.