MB39C601 Datasheet, PDF (19/37 Pages) Cypress Semiconductor – High power factor in single conversion

MB39C601
8.9 TZE Part
MB39C601 requires all of the following three conditions in order to start the next switching cycle.
1. The time since the last turn-on edge must be equal to or longer than the switching time set by IFB.
2. The time since the last turn-on edge must be longer than the minimum switching period set by MB39C601 (nominally 7.5µs
which equals 133 kHz).
3. Immediately after zero energy detection at the TZE pin. Or, the time since the last zero energy detection must be longer than
tWAIT, (TZE) (2.4μs or less).
Starting switching cycle diagram
The TZE pin is connected with Auxiliary Winding of the transformer through the resistance division, and detects zero energy as
shown "TZE pin Connection".
A delay, 50ns to 200ns, can be added with CTZE to adjust the turn-on of the primary switch with the resonant bottom of Primarty
Winding waveform.
Switching Waveform at detecting zero Energy
Document Number: 002-08393 Rev.*A
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