IR’s SmartRectifier Slashes Parts Count by 75 Percent
International Rectifier (IR) today introduced the IR1167 SmartRectifier™ IC for ac-dc power converters for laptops, mini-PCs, LCD and PDP televisions, game systems and other digital computing and home entertainment systems. The SmartRectifier IC simplifies and improves efficiency in secondary synchronous rectification (SR) in high power flyback and resonant half-bridge converter circuits, enabling smaller, cooler designs.
"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 new SmartRectifier IC employs a new technique for precise, direct sensing of voltage thresholds across the SR MOSFETs, allowing fast, accurate control to minimize power losses," said Stephen Oliver, marketing manager at International Rectifier.
"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," Oliver added.
The IR1167 SmartRectifier IC uses IR's proprietary HVIC technology, making it compatible with all MOSFET gate types and offers direct connection to IR's range of 30V to 200V SR MOSFETs.
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," and California Energy Commission (CEC) 80Plus™ compliance.
"Previously, synchronous rectification in resonant half-bridge topologies has not been commercially viable due to the complexity of varying system frequency and low standby power regulations. Here, the IR1167 enables simple SR for a major boost in system efficiency," Oliver added.
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).
Samples are available. 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.
