INTERNATIONAL Rectifier has released the IR3093, a three-phase interleaved pulse width modulation (PWM) control IC that supports the AMD Athlon, AMD Opteron, AMD Athlon64 and Intel VR10.X processors. Applications include desktop computer motherboards, voltage regulator modules (VRM), video graphics cards and telecom single in-line modules.
The IR3093 is suitable for space-constrained systems requiring greater than 60A of load current. It integrates MOSFET drivers, reducing part count by 75%. The end result is simplified circuit design, improved system reliability and reduced solution size.
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 minimise switching losses and increase efficiency. A programmable oscillator with a frequency range of 100kHz to 540kHz gives additional flexibility to improve system efficiency and transient response.
The IC has programmable soft-start and hiccup over-current protection. Current sensing is achieved with loss-less inductor current sensing which improves accuracy. Dual under-voltage lockout circuits and over-voltage protection ensure reliability of system voltages. A power-good output signal indicates proper operation.
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 minimising output capacitor requirements. A body braking circuit reduces the output capacitance requirement by an additional 25%.
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.