Chipset Bolsters Next-Gen AMD Processors

Forecasting best-in-class efficiency over the entire load range for next-generation AMD processors, the IR3521 and IR3529 XPhase chipset packs a plethora of features. The IR3521 control IC supports I²C serial communications to provide overall system control, interfacing with any number of phase ICs, each driving and monitoring a single phase. Paired with the IR3529 phase IC, the IR3521 enables phase dropping to improve the light load performance of the power supply. The IR3529 phase IC features a power state indicator to maximize efficiency at light loads as well as enhanced driver capability and reduced non-overlap time. Turbo is also on tap to improve load turn-on response. The device also incorporates novel features that greatly enhance the transient response of the converter to reduce overall design size and cost. The IR3521 control IC provides outputs for both the Vdd core and VDDNB auxiliary planes required by the AMD CPU and features high speed error amplifiers with a bandwidth of 20 MHz and slew rate of 10 V/ms. Remote sense amplifiers provide differential sensing and require less than 50 mA of bias current. The IR3529 phase IC features anti-bias circuitry, 7V/4A gate drivers (6A GATE L sink current), and supports loss-less inductor current sensing and a converter output voltage up to 5.1V. It also implements cycle-by-cycle over-current protection to resolve high repetition load transients. Pricing for the IR3521TRPbF begins at $1.90 each/10,000. For more information, contact Sian Cummins at INTERNATIONAL RECTIFIER CORP., El Segundo, CA. (310) 252-7148.