International Rectifier has launched the IR1167 SmartRectifier IC to simplify and improve efficiency in secondary synchronous rectification (SR) in high power flyback and resonant half-bridge converter circuits. Typical applications include AC-DC power converters for laptops, mini-PCs, LCD and PDP televisions, game systems and other digital computing and home entertainment systems. In 100W to 300W flyback circuits, traditional complex and bulky current transformer control circuits waste energy because large reversing currents are required to sense polarity shifts through the SR MOSFETs. In contrast, IR’s SmartRectifier IC employs a technique for precise, direct sensing of voltage thresholds across the SR MOSFETs, allowing fast, accurate control to minimize power losses. The IR1167 can increase overall system efficiency by 1 percent and reduce MOSFET temperature by 10 degrees, while slashing SR parts count by 75 percent.
The IC uses IR’s proprietary HVIC technology, making it compatible with all MOSFET gate types and offers direct connection to IR’s wide range of 30V to 200V SR MOSFETs. The benefits of the IC are further enhanced when used with IR’s MOSFETs featuring optimized on-resistance and gate charge characteristics, such as the IRF7853, IRFB4110 and IRFB4227. These optimized MOSFETs work with the IR1167 as a “total chip set solution” to further maximize efficiency and power density in SR circuits. Since the new IC works independently from the primary control, it can be used in a variety of transformer switching modes and applications with capacitive output filters. Independence from the primary side means that the IR1167 operates in low power “burst modes” to enable “1W Standby”. The SmartRectifier technique halves the losses dissipated in the SR MOSFET. This reduces the number of MOSFETs needed or allows a change from large TO-220 packages to small, surface mount SO-8 parts. The IC is available in either SO-8 or DIP-8 packages which are lead-free (PbF) and compliant with the Restriction of Hazardous Substances Directive (RoHS).
In addition to data sheets, application notes and technical papers, new SmartRectifier online design software is now available on IR’s myPower site. Designers enter application conditions and performance requirements to obtain recommended IC and MOSFET chip sets which can be sorted by performance and system cost. Daughter cards are available. Samples are available through product marketing.
Pricing is US $1.08 each for the IR1167A/BSPbF and US $1.11 each for the IR1167A/BPbF, each in 10,000-unit quantity. Pricing is subject to change.
