about switch power supply

Thread Starter

xljin2014

Joined Nov 11, 2014
33
Screenshot_20210731_110311.jpg
hi. friends.
this is a switch power supply circuit.I have two questions: 1. why the secondary part don't have diode?how to rectify? 2.what is the function of the capacitor near the resistor of the primary side?
 

Attachments

Thread Starter

xljin2014

Joined Nov 11, 2014
33
Because the AOZ7648 is a synchronous rectifier
http://www.aosmd.com/res/data_sheets/AOZ7648QI-06.pdf

It's part of the RCD suppression circuit to prevent overshoot of the primary voltage.
sorry I don't quite understand of your reply. I need more detailed explanation.
1.I think AOZ7648 is an ic that takes secondary circuit outputs and give feedback signals of TXN and TXP. how it works as a synchronous rectifier?
2. how's the capacitor do to make a RCD surprenssion?
 

Ian0

Joined Aug 7, 2020
3,238
Top