Controller powers up Pentium 4 platforms

The Endura ISL6565 is a three-phase synchronous-buck PWM controller IC for powering Intel Pentium 4 processors on VR 10.X platforms.

The Endura ISL6565 is a three-phase synchronous-buck PWM controller IC for powering Intel Pentium 4 processors on VR 10.X platforms.

The ISL6565 offers higher integration, lower overall solution cost, both popular current sensing topologies, and the precision voltage control that is required for next-generation VR 10.X platforms to ensure stable upset-free operation of the CPU.

This precision is partly attributed to the ISL6565's on-chip current sense temperature compensation, 0.5% system voltage accuracy, remote voltage sensing, Intersil's Dynamic VID technology and voltage offset control.

A and B versions of these ICs offer designers the choice of either on-resistance current sensing (ISL6565A) or inductor DC resistance (DCR) current sensing (ISL6565B).

These cost- and space-saving methods of current sensing make it possible to meet VR 10.X platform specifications for accurate load line programming, sometimes referred to as output voltage droop.

Additionally, current sensing is used for phase-to-phase balancing and overcurrent protection.

To help ensure the accuracy of droop, programmable internal temperature compensation is provided to compensate for the effect that changes in temperature have on the lower mosfet's on-resistance and output inductor DCR current sense elements.

A unity-gain differential amplifier is provided for remote voltage sensing, which provides the advantage of avoiding any voltage potential difference between remote and local grounds that would otherwise introduce error and degrade voltage accuracy.

The precision threshold-sensitive enable input is available to accurately co-ordinate the start up of the ISL6565A and ISL6565B with Intersil's mosfet driver ICs.

Intersil's Dynamic-VID technology allows seamless on-the-fly voltage changes using the voltage identification (VID) bus.

The offset pin allows accurate voltage offset settings that are independent of VID bus setting.

The high 1.5MHz maximum per-phase switching frequency of the ISL6565 ensures very low high-frequency ripple voltage that is easily filtered using smaller inductors and fewer than usual capacitors.

This saves space and cost.

The ISL6565A and B are offered in near-chip-scale 28-pad 5 x 5mm quad flat no-lead (QFN) and 28-lead TSSOP packages.

The QFN package provides enhanced thermal efficiency by transferring heat directly to the printed circuit board via a copper land on the ICs underbelly and the perimeter contact pads.

The ISL6565 can run three phases at maximum switching frequency without the need for additional and costly heatsinking.

The ISL6565 is available now.

The suggested resale price in 100- to 999-unit quantities is $2.15 for each IC.

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