Dual-Phase IC Saves Power In Each Phase Independently

Offering an independent power-saving function for energy-efficient multiphase server applications, the IR3527 XPhase dual-phase IC drives and monitors two phases of a multiphase synchronous buck converter to significantly reduce overall system cost as well as the size of the complete circuit. The IR3527 implements an independent power savings function (PSI) for each power stage and sequential phase timing for use in single-output multiphase converters. When the power-saving mode is enabled, the power stage disables its output, eliminating switching losses while the correct converter operation is maintained by the single power stage or in conjunction with other converter power stages. Moreover, the IR3527’s current-sense amplifiers remain active when in power-savings mode to support adaptive voltage positioning. The device features converter output voltage up to 5.1 V, lossless inductor-current sensing, feed-forward voltage-mode control, and an integrated bootstrap synchronous PFET. In addition, the IR3527 provides self-calibration of PWM ramp, current-share amplifier and single-wire bidirectional average current sharing as well as a debugging function to isolate the phase from the converter. The device is available in a small thermally enhanced 24-lead, 4 x 4-mm MLPQ package and is RoHS compliant. Pricing for the IR3527TRPBF starts at $1.50 each in lots of 10,000. Production orders are available immediately. INTERNATIONAL RECTIFIER, El Segundo, CA. (310) 726-8000.