El Segundo, Calif.—International Rectifier says its IR1166 SmartRectifier IC for AC/DC power converters boosts overall system efficiency by 1 percent while using 75 percent fewer components.
The chip simplifies the design of mid-power secondary synchronous rectification (SR) circuits in resonant half-bridge converters and flyback converters designed for
50-150 watt discontinuous conduction mode (DCM), critical conduction mode (CrCM), and continuous conduction mode (CCM). "IR's new SmartRectifier IC uses a new technique for precise, direct sensing of voltage thresholds across the SR MOSFETs, allowing fast, accurate control to minimize power losses in mid-power flyback circuits," said Mario Battello, marketing manager. "In contrast, traditional complex and bulky current transformer control circuits waste energy because of the large reversing currents required to sense polarity shifts through the SR MOSFETs. Compared to discrete solutions, IR1166S increases overall system efficiency by one percent while using 75 percent fewer components, and allowing a 25 percent reduction in SR system cost."
The IR1166 works independently from the primary control and enables synchronous rectification so it can be used in a variety of transformer switching modes and applications with capacitive output filters. When "burst mode" occurs on the primary side, the secondary side remains unaffected, complying with California Energy Commission 80Plus and "1W Standby" specs.
This device, based on IR's proprietary high voltage IC (HVIC) technology, is compatible with all MOSFET gate types, and offers a direct connection to a wide range of 40- to 200-volt SR MOSFETs. When used with the company's standard and logic-level HEXFET power MOSFETs, the chip cuts losses in the SR MOSFET by 50 percent, according to the company, thus cutting the number of MOSFETs needed in the circuit or enabling the use of smaller packages.
Click here for the product datasheet, application notes and technical papers.
SmartRectifier design software is available on-line by clicking here. Daughter cards are also available that offer a fast and simple way to compare the efficiency and simplicity of the SmartRectifier solution to alternative approaches in existing designs.
The IR1166 is available in an SO-8 package and soon in a DIP-8 package, which are both lead-free (PbF) and compliant with the Restriction of Hazardous Substances Directive (RoHS). The IR1166SPbF, IR1166STRPbF and IR1166PbF are priced at 70 cents each in 10k-unit quantities. Production quantities are available immediately. Pricing is subject to change.
A 100-watt flyback converter reference design (IRAC1166-100W) will be available that operates in CrCM. The reference design demonstrates the SmartRectifier features by resolving the output rectification function using a combination of one IR1166SPbF IC and two IRF7853 (SR) MOSFETs in parallel. The three-package solution requires no heatsink.
International Rectifier, 1-310-252-7105, www.irf.com