J2

2 Ttotal Vin min ) Vin min Another design criterion is the high current ripple in CRM. As a result of the high ripple, the core flux swing is bigger compared to the CCM mode. Higher flux swing results in higher core losses and rules out materials such as powdered iron. Detailed discussion on properties of the material is beyond the scope of this paper, but it is something to keep in mind in the design of the inductor. It is apparent from the above equations that the follower boost approach...

Rmk

As sketched by Figure 37, a portion of the average input voltage should be applied to pin2. The NCP1605 incorporates a comparator to monitor Vpin2 and inhibits the circuit when this voltage is lower than the internal brown-out threshold. More specifically, the internal comparator features a 50 hysteresis (VboL 50 VboH) to take into account the change in the input voltage average level 1. Before operation, the PFC stage is off and the input bridge acts as a peak detector (refer to Figure 38). As...