The UCG2882x supports minimum 2× transient peak output power capability for applications which require bursts of high power for short durations of time. The peak power is achieved without the need for oversizing the various components such as the transformer, power FETs, and so forth, and the same flyback design is usable for minimum 2× the continuous output power rating for short durations. With the peak power handling capability, a 65W flyback converter designed with UCG28826 can deliver a minimum 130W transient peak output power for a maximum 120ms duration during high line and 10ms during low line operating conditions.

At high line input, the transient peak power delivery happens in DCM/QR modes of operation and is limited to maximum 120ms duration as per OPPH protection, as described in Section 7.4.10.4. At low line input, due to limitations in power delivery from DCM/QR modes, the continuous conduction mode (CCM) extends the operation to minimum 2× the nominal power rating, and limited to maximum 10ms in duration. To limit the converter from excessive output power delivery at high line input, the CCM mode is disabled for input bulk capacitor voltage higher than 200V DC. Further, CCM mode of operation at low line input (<200V DC) is limited to 10ms maximum and device returns to 1st valley QR mode of operation if the transient output load does not reduce by the time of expiration of the 10ms timer. The CCM mode of operation is described in Section 7.4.2.4. Peak power delivery in DCM/QR modes at higher than 140W for longer than 120ms triggers OPPH fault, as detailed in Section 7.4.10.4. A minimum 2× transient output power is supported, while maximum instantaneous transient output power in DCM/QR/CCM modes depends on the input bulk capacitor voltage and the power stage component values and is limited in time by the respective CCM, OPPH, and OPPL timers.