IR Introduces High Efficiency Solution to Power DDR3 Memory Modules

The IR3522 dual output PWM controller with built-in I(2)C interface provides overall system control for both the DDR3 VDDQ and Vtt rails. The device interfaces with any number of IR3506 phase ICs to drive as many phases as needed to power any number of DDR3 dual in-line memory modules (DIMMS), simplifying layout, reducing board space, and overall system cost. The IR3522/IR3506 chipset enables accurate tracking with the additional flexibility of margining between the VDDQ and Vtt outputs through the I(2)C interface.

"The new Xphase solution for DDR3 applications delivers a power supply that is smaller, more flexible and easier to design while providing higher efficiency from light load to full load when compared to conventional approaches. The IR3522 combines the best of both worlds: precision of analog control combined with programmability of power management functions via I(2)C to implement a simple but smart memory power supply," said Omar Hassen, executive director, IR's Multiphase Products, Enterprise Power Business Unit.

The IR3522 allows output voltage programming capability for both VDDQ and Vtt outputs through the I(2)C compatible interface with a VDDQ set point error of only +/-0.5 %. The IR3506 provides both source and sink capability to enable more accurate tracking of the Vtt output to VDDQ. In addition, the IR3506 supports a power savings function (PSI) to maximize efficiency at light loads.

IR3522 Features

The IR3522's I(2)C interface programs the Vtt tracking ratio ± 25 % and provides digital ON/OFF control. Four I(2)C addresses are selectable using two ADDR pins while four different VREF1 voltages are selectable using two VID pins if I(2)C communication is not available. Soft-stop turn-off to ensure VDDR and Vtt tracking is also featured, in addition to a fault activated Crowbar pin to drive external NMOS devices for external output voltage protection. As with all Xphase ICs, the IR3522 features a comprehensive set of protection features including over-current, over-voltage, open remote sense, and open control.

IR3506 Features

The IR3506 phase IC features 7V/2A gate drivers (4A GATEL sink current) and supports loss-less inductor current sensing. The device also features a soft-stop turn-off to ensure VDDR and Vtt tracking. The IR3506 also offers over-current protection during PSI assertion mode operation, integrated bootstrap synchronous PFET, debugging function, self-calibration of PWM ramp, current sense amplifier, and current share amplifier and single-wire bidirectional average current sharing.

More information is available on the International Rectifier website at http://www.irf.com/whats-new/nr091015.html.

Availability and Pricing

Pricing for the IR3522TRPBF begins at US $1.90 each in 10,000-unit quantities while pricing for the IR3506TRPBF begins at US $0.90 each in 10,000-unit quantities. Production orders are available immediately. Prices are subject to change.

About XPhase(R)

XPhase is IR's distributed multiphase architecture that consists of control ICs and phase ICs that communicate using a simple six-wire bus scheme. Phases can be added or removed without changing the fundamental design. The six-wire bus consists of a three-wire digital phase timing bus, an average current, an error amplifier output and a VID voltage. By eliminating point-to-point wiring between the control and the phase ICs, the six-wire bus shortens interconnections, and reduces parasitic inductance and noise. This simplifies PCB layout and provides a more robust design.

About International Rectifier

International Rectifier (NYSE:IRF) is a world leader in power management technology. IR's analog and mixed signal ICs, advanced circuit devices, integrated power systems and components enable high performance computing and reduce energy waste from motors, the world's single largest consumer of electricity. Leading manufacturers of computers, energy efficient appliances, lighting, automobiles, satellites, aircraft and defense systems rely on IR's power management benchmarks to power their next generation products. For more information, go to www.irf.com.

Trademark Notice

IR(R) and XPhase(R) are trademarks of International Rectifier Corporation. All other product names noted herein may be trademarks of their respective holders.

SOURCE: International Rectifier

International Rectifier 
Sian Cummins, 1-310-252-7148 
scummin1@irf.com