AC-DC Bridge Rectifiers Enable Thermal Enhancement

Alpha and Omega Semiconductor Limited (AOS) announced a new family of active AC-DC bridge rectifiers. Aptly trademarked AlphaZBL for “zero bridge loss,” this new family of products virtually eliminates the bridge rectifier losses in AC-DC power supplies and adaptors. Typical end applications include high power 100W and above adaptors used for high-end laptops and televisions as well as power supplies for Desktops, Game consoles, Servers, and Telecom.

The first two members of the family include a controller, AOZ7200, in a SOT-23 package and an integrated product AOZ7270, which integrates a 600V, 190mOhm MOSFET in a DFN 5x7 package. The AOZ7200 offers maximum flexibility to trade off performance and cost by pairing it with AOS’s benchmark super junction family of MOSFETs. The AOZ7270 takes advantage of AOS’s capabilities in novel IC design, benchmark MOSFET technology, and innovative packaging to reduce component count and design time. Both products are self-powered from the AC line and do not require external circuitry. The proprietary self-biasing scheme sips minimal power from the AC line making it very efficient in light load or standby mode of operation.In a typical 100W application, the AOZ7270DI delivers efficiency improvements of 0.89% at 115VAC and 0.44% at 230VAC over a diode bridge. Both products exceed lightning surge requirements that are a critical requirement in AC-DC applications.

Technical Highlights

• Synchronous rectifier replacement for lossy high voltage bridge rectifier
• Self-powered Vcc in AC system with ultra-low quiescent current
• Integrated 190mOhm, 600V N-channel MOSFET (AOZ7270DI)
• A low reverse threshold of 1mV for improved efficiency

Pricing and Availability

The AOZ72xx series is immediately available in production quantities with a lead-time of 12 weeks. The unit price for 1,000 pieces is $0.47 for AOZ7200CI, and $1.48 for AOZ7270DI.

For more information, please visit AOS's website.