NCP1654BD133R2G

The NCP1654 is a PFC driver designed to operate in fixed frequency, continuous conduction mode. The fixed frequency operation eases the compliance with EMI standard and the limitation of the possible radiated noise that may pollute surrounding systems. In addition, continuous conduction operation reduces the application di/dt and their resulting interference. More generally, the NCP1654 is an ideal candidate in systems where cost - effectiveness, reliability and high power factor are the key parameters. It incorporates all the necessary features to build a compact and rugged PFC stage:

· Compactness and Flexibility: housed in a SO8 package, the NCP1654 requires a minimum of external components. In particular, the circuit scheme simplifies the PFC stage design and eliminates the need for any input voltage sensing. In addition, the circuit offers some functions like the Brown - Out or the true power limiting that enable the optimizations of the PFC design.

· Low Consumption and Shutdown Capability: the NCP1654 is optimized to exhibit consumption as small as possible in all operation modes. The consumed current is particularly reduced during the start - up phase and in shutdown mode so that the PFC stage power losses are extremely minimized when the circuit is disabled. This feature helps meet the more stringent stand - by low power specifications. Just ground the Feed - back pin to force the NCP1654 in shutdown mode.

· Undervoltage Protection for Open Loop Protection or Shut - down: the circuit detects when the feed - back voltage goes below than about 8% of the regulation level. In this case, the circuit turns off and its consumption drops to a very low value. This feature protects the PFC stage from starting operation in case of low AC line conditions or in case of a failure in the feed - back network (i.e. bad connection).

· Fast Transient Response: given the low bandwidth of the regulation block, the output voltage of PFC stages may exhibit excessive over or under - shoots because of abrupt load or input voltage variations (e.g. at start up).