Date: 16/04/2009

Rectifier driver IC to drive N-Channel MOSFETs in resonant half bridge topology

International Rectifier (IR) has added a new member to its SmartRectifier ICs family coded IR1168 for AC-DC power converters for high-end LCD TVs.

The 200V dual smart secondary-side rectifier driver IC is designed to drive two N-Channel power MOSFETs used as synchronous rectifiers (SR) in resonant half-bridge topologies.
IR says, In contrast to traditional current transformer SR methods, the IR1168 accurately determines turn-on and turn-off based on MOSFET drain sensing voltage in close proximity to zero current transition, eliminating the need for additional components to simplify design. IR also claims, an efficiency improvement of 1.5% for a standard 240W LCD TV SMPS by using this IC.

"While synchronous rectification provides significant energy savings compared to diode-based designs, traditional SR methods are complex and require a high component count. Using only two gate resistors and a supply capacitor, the IR1168 delivers a lower system temperature and increased power density for even greater efficiency and reliability than existing SR methods while simplifying design and drastically reducing component count to shrink PCB size," said Tom Ribarich, director, IR's Energy Saving Products Business Unit.

The IR1168 supports burst mode operation to increase the efficiency at light loads. Advanced blanking scheme and double-pulse suppression features allow reliable operation in fixed and variable frequency applications. Other key features include maximum 500kHz switching frequency, anti-bounce logic and UVLO protection, 4A peak turn-off gate drive current, micropower start-up and ultra low quiescent current, 10.7V gate drive clamp, 70ns turn-off propagation delay and a wide Vcc operating range from 8.6V to 18V.

Package: 8-pin SOIC
RoHS compliant: Yes
Availability: Now in volumes
Price: Each US $1.50 for 10K pieces