EL SEGUNDO, Calif. - International Rectifier, IR® (NYSE: IRF) today introduces the IRU3055CQ five-bit programmable, three-phase PWM controller IC with integrated MOSFET drivers. The IRU3055CQ is specially designed for the new GHz class CPUs requiring low voltage and high current. The new device meets the Intel VRM 9.0 specification and provides a cost-effective solution for multiphase buck converters that power CPUs in servers, advanced desktop computers and motherboards using the Intel® Pentium™ 4 and other processors.

Reza Amirani, Director of Applications for DC-DC Power Management ICs at International Rectifier said, "International Rectifier has expanded its line of multiphase PWM ICs with the introduction of the IRU3055CQ. IR's extensive selection of analog ICs and discrete power semiconductors gives designers a wide range of options for every power management socket in computing PCBs."

The IRU3055CQ has on-board MOSFET drivers, making it cost-effective compared to the majority of multiphase controllers that require external MOSFET drivers. When used with IR's HEXFET® power MOSFETs like the IRF3704S in the control FET socket and the IRF3711S in the synchronous FET socket, the IRU3055CQ can provide up to 60A for microprocessor VCORE requirements.

The new controller IC is a fixed-frequency voltage mode controller with 50kHz to 500kHz programmable operating frequency. The output voltage is selectable in 25mV steps from 1.075 to 1.85V with up to 1.0% output voltage accuracy using a programmable VID code to the five-bit digital-to-analog converter (DAC).

The new device has a number of features to provide protection and monitoring for the power system and the microprocessor. It features under-voltage lockout (UVLO) for the 5V and 12V supplies as well as an externally programmable soft-start function. Another feature is the PGOOD monitor circuit, which is held low if the output of the converter is not within ±10% of the programmed voltage.

The IRU3055CQ also provides over-voltage protection. If the output voltage exceeds the DAC-programmed voltage by 20%, the low-side MOSFETs turn on and shunt the output voltage to ground, protecting the CPU from damage. The IRU3055CQ features loss-less inductor current sensing and sharing while over-current protection is achieved by synchronous FET RDS(on) sensing, eliminating the need for a separate sense resistor. The IRU3055CQ can also be easily configured for voltage droop compensation, so that the output voltage will linearly decrease as load current increases and vice versa, as required by VRM specifications.

Price and Availability

The IRU3055CQ in the 36-pin wide body QSOP package is available immediately. Pricing is US$2.24 each in 10,000-piece quantities.

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