Abstract- Subharmonic oscillation is  widely studied in switching  converters  under  current  mode  control  (CMC). Its boundary of occurrence in the design parameter space is well known in the case of an infinite-bandwidth current sensor.  However,  in  a  practical  implementation,  either  a limited-bandwidth current sensor or an additional filter is used. This could have an effect on the system dynamics particularly for relatively high switching frequencies.

Abstract—The design of efficient single-stage high brightness light-emitting diodes (HBLEDs) ac–dc drivers with power factor correction (PFC) in low-power applications is addressed in this paper. The PFC is achieved by using a switching converter with both step-up and stepdown voltage capability. It is well known that a good tracking of the input reference current close to the zero crossing is challenging, in particular when the LED output current is low, hence jeopardizing the power quality at low power levels.