Two-phase PWM controller

International Rectifier’s IR3092 is a two-phase interleaved pulse width modulation (PWM) control IC that supports the AMD Athlon, Athlon64, Opteron, and Intel VR10.X processors.

Applications include server and desktop computer motherboards, voltage regulator modules (VRM), video graphics cards and telecom single in-line package (SIP) modules. The IR3092 is targeted at space-constrained systems with high load current and efficiency requirements.

Compared to competitive devices that require external gate drive circuits, the IR3092 includes integrated MOSFET drivers with 3.5A drive capability. Existing two-phase solutions that are implemented with three ICs can now be replaced with a single IR3092 improving system reliability, reducing board area and simplifying circuit design.

A patent-pending body braking circuit reduces the output capacitance requirement by up to 25% further reducing system costs. The IR3092 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 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 IR3092 features programmable soft-start and hiccup over-current protection. Current sensing is achieved with loss-less inductor current sensing which gives improved 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 minimising output capacitor requirements. The IC is also capable of 100% duty cycle operation to further improve transient response.In addition, the IR3092 features programmable slew rate response to ‘on-the-fly’ VID code changes.

The IR3092M PWM IC is available immediately in the MLPQ-48, 7×7 package. Pricing for the new IC is US $2.50 each in 10,000-piece quantities.