There has been a notable increase in attention towards battery chargers for battery-powered applications (BPAs). Even with higher power demand of the BPAs, consumer requirements like small size, light weight and low cost of the chargers shall not be compromised. These requirements together with many different electrical and normative specifications like wide input- and output voltage range, stand-by power consumption, high efficiency etc. rise a new challenge for the currently used converter topologies. In addition, requirements for a high power factor play a stronger role. In order to meet all demands and achieve a high power density, the hybrid-flyback converter, also known as asymmetrical half-bridge, is proposed as dc-dc stage for the battery charger. Compared to conventional topologies like (active-clamp) flyback and LLC-resonant converter, a design using the hybrid-flyback results in a small transformer size even in wide input- and wide output voltage range as well as good light load efficiency. All this can be supported at moderate cost level. In the presentation two design examples of the charger using the hybrid-flyback, with and without upfront PFC stage, are presented.
