LNK363 design from pi_expert problemhi
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hi,dear pi engineer. please see the attached pic. this is a design from the pi_expert. can u tell me how to design the clamp circuit which includes VR1 and D5? and what is the operation principal of this circuit? do u have some materials related with this issue? thank u in advance.
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ok. thank u.
you are welcome
We do not have any application notes that describe the tuning for a DRAIN clamp circuit. Basically what you want is to clap the transformer’s leakage inductance spike. This spike happens every time the controller switches OFF. The smaller your leakage inductance, the smaller the voltage flying spike. You can find the basic theory in switching power supplies books. One very good book is Switching Power Supply Design and Optimization by Sanjaya Maniktala.