The peak current threshold of the OPP curve is used to initiate the 160-ms timer, while the peak power limit (PPL) determines the highest controllable peak current of the peak current loop, V_CST(MAX). Regardless of V_VS, the ratio between V_CST(MAX) and V_CST(OPP) is fixed at approximately 4/3. In other words, this feature provides the highest short duration peak power (P_O(MAX)) that the converter can deliver. The line-dependent PPL curve is able to achieve a consistent peak power level over a wide input voltage range. As an example, to supply a highest peak power of 150% of nominal rated load, choose an R_CS value that ensures that the peak current threshold at 150% load and V_BULK(MIN) must not be above V_CST(MAX). Then, the threshold of the OPP power (P_O(OPP)) can be programmed to approximately 112% to support 150% peak power design, based on the following equation.

Additionally, before V_O reaches steady-state regulation during V_O soft-start, the highest V_CST can also reach V_CST(MAX). The transformer maximum flux density must have sufficient design margin to the high-temperature saturation limit of the core material at the peak current while in PPL.