KP, KRP, KP_TRANSIENT ?
I´m designing an 8W 5V/12V flyback SMPS with TNY278. In PIExpert design results, the KP parameter is the same that KRP? What does the KP_TRANSIENT parameter mean? Thank you very much.
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To piggy back on this comment thread, I'm having trouble with the parameter as I am trying to design for output current of 0.36A with the LNK3206D but with a inductor of 470 uF I am above 0.2 KP_TRANSIENT but the inductor value is too small.
So when I increase the size of the inductor to 1200 or 1400uH, the KP_Transient drops to 0.09 which is another violation. I noticed that the design is setup as a MCCM. I am trying to design for CCM.
Would really like to know how I can make this work. Thanks!
Hi saiknaram,
Good day!
Your inquiry has already been acknowledged by our representative and will be attended in a while. He will reply in your recent posting.
Thank you and regards,
PI-Lupin
In TinySwitch 9on off control) KP is the on an average basis indication of how continuous the design runs. Usually KP is above 0.35 for most designs. This is used in determining the primary inductance value.
The KP-TRANSIENT is the cycle by cycle based worst case KP ratio (ratio od ripple current to peak current). This ratio needs to be above 0.25 in order to maintain proper operation.