International Rectifier Introduces Three-Phase PWM Control IC with Integrated Drivers for Desktop Computers

International Rectifier (IR) introduced the IR3093, a three-phase interleaved pulse width modulation (PWM) control IC that supports several microprocessor families: AMD Athlon^TM, AMD Opteron^TM, AMD Athlon64^TM and Intel® VR10.X processors. Typical applications include desktop computer motherboards, voltage regulator modules (VRM), video graphics cards and telecom single in-line (SIP) modules.

The IR3093 is suitable for space-constrained systems requiring greater than 60A of load current. In comparison to competitive devices that require external gate driver ICs, the IR3093 integrates MOSFET drivers, reducing part count by 75%. The end result is simplified circuit design, improved system reliability and reduced solution size. Together with IR's DirectFET^TM technology MOSFETs, circuit designers can realize an efficient, space-saving solution.

The term BTX (balanced technology extended) refers to a personal computer form factor specification created to standardize size, performance, features and cost.

Technical Highlights
The IR3093 operates from a single 12V supply and includes a linear regulator to power the gate drivers. The regulator output voltage can be programmed to minimize switching losses and optimize efficiency. A programmable oscillator, with a frequency range of 100kHz to 540kHz, gives the designer additional flexibility to improve system efficiency and transient response.

For system protection and reliability, the IR3093 features programmable soft-start and hiccup over-current protection. Current sensing is achieved with loss-less inductor current sensing which improves accuracy compared to sensing circuits measuring MOSFET on-resistance. Dual under-voltage lockout circuits and over-voltage protection ensure reliability of system voltages. A power-good output signal indicates proper operation.

To meet the stringent power requirements of today's microprocessors, the output voltage can be programmed with either a five- or six-bit voltage identification (VID) code with 0.5% set-point accuracy. An adaptive voltage-positioning feature maintains the output voltage tolerance while minimizing output capacitor requirements. A patent-pending body braking circuit reduces the output capacitance requirement by an additional 25% further reducing system costs.

Following the trend of increasing power requirements in microprocessors, the IR3093 is pin-compatible with the two-phase IR3092, giving designers the flexibility to migrate from a two-phase design to a three-phase solution with a single PCB layout. This feature can save significant development time as designs incorporate more advanced microprocessors.

Availability and Pricing
The IR3093M PWM IC is available immediately in the MLPQ-48, 7 x 7 package. Pricing is US $3.10 each in 10,000-unit quantities.

IR3093M Datasheet