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Intersil's Two New PWM Controller ICs Supply Precision Core Power Control for VR10.X Platforms

-- New ICs offer precision-performance with 6-bit Dynamic VID in a small 5 X 5 mm QFN package

MILPITAS, CA, January 23, 2003 – Intersil Corporation (NASDAQ: ISIL), a world leader in the design and manufacture of high performance analog and wireless networking solutions, today announced the new Endura™ ISL6556A and ISL6556B precision multiphase PWM controller ICs. These new controllers provide the stability and precision required to power the new-generation VR10.X processors while conserving board space and reducing manufacturing costs. They are also backward compatible with VR9.X platforms.

Both new multiphase controllers enable the manufacture of VRM10 motherboards at a lower cost due to the use of lower-cost components, lower external component count, easier layout and smaller board area. Package options include the 28-lead SOIC and the space-saving 32-pad 5 X 5 mm Quad Flat No-lead (QFN) packages.

“The ISL6556A and ISL6556B represent Intersil’s continuing ability to provide the industry’s highest performance-to-price ratio in advanced CPU power solutions,” said Rick Furtney, vice president and general manager of Intersil’s High Performance Analog Product Group. “We reaffirm our pledge to provide our industry partners with power solutions that ensure reliability, high performance and cost competitiveness.”

The ISL6556A/B ICs provide core voltage regulation by driving up to 4 synchronous-rectified buck channels in parallel. Both devices feature the industry’s best 0.5% reference voltage tolerance. This extremely tight tolerance allows better loadline adherence than competitive solutions and also results in fewer components, lower cost, reduced power dissipation, and a smaller implementation area.

A unity gain, differential amplifier is provided for remote voltage sensing. Any potential difference between remote and local grounds is virtually eliminated using the remote-sensing amplifier.

MOSFET RDS(on) current sensing is used to measure current in each phase and also to generate droop current. RDS(on) current sensing has been demonstrated to provide the most accurate loadline adherence. Accuracy of Droop is ensured with the use of a Negative Temperature Coefficient (NTC) compensation circuit that is used to nullify the effect of RDS(on) temperature sensitivity. The use of temperature compensation with the competing inductor DCR (DC Resistance) sense methods only partially addresses the problems with those methods. The ISL6556A employs an external NTC circuit while the ISL6556B has the NTC thermistor on-chip, saving part cost and board space without sacrificing performance.

A threshold-sensitive enable input is available to accurately coordinate the start up of the ISL6556A with any other voltage rail. Dynamic VID™ technology allows seamless on-the-fly VID changes. The offset pin allows accurate voltage offset settings that are independent of VID settings. The ISL6556A/B ICs use a 5-V bias and have a built-in shunt regulator to allow 12-V bias using only a small external limiting resistor. Both ICs offer +/- 0.5% system accuracy over life, load, line and temperature.

6556 Features Summary

• Precision multiphase core voltage regulation
  • Differential remote voltage sensing
  • ±0.5% system accuracy over life, load, line and temperature
• Precision RDS(on) current sensing
  • Accurate load-line programming
  • Accurate channel-current balancing
  • Low-cost, loss-less current sensing
• Internal shunt regulator for 5-V and 12-V biasing
• Microprocessor Voltage Identification (VID) input
  • Dynamic VID technology
  • 6-bit VID input - 0.8375 V to 1.600 V in 12.5-mV steps
• Threshold-sensing enable function for synchronizing with driver Power-On-Reset for proper sequencing
• Over-current protection
• Over-voltage protection
  • No external components needed
  • OVP pin to drive crowbar device
• 2-, 3- or 4-phase operation
• Switching frequency to 1 MHz
• 28-lead SOIC and 32-pad 5 X 5 mm QFN package options

The ISL6556A/B ICs interface with Intersil’s MOSFET driver ICs, such as the HIP6601B, HIP6602B, HIP6604B, or ISL6605, to create a compact, high-performance, VR10.X- or VR9.X-compliant, cost-effective power solution. These drivers also come in space-saving QFN packages. Reference designs and evaluation platforms are available. Visit Intersil’s Endura Power Management Web site at: intersil.com/design/powermanagement/index.asp

6556 Availability and Pricing
The ISL6556A and ISL6556B are available now. Pricing is for thousand unit quantities: ISL6556ACB (SOIC) - $1.85, ISL6556ACR (QFN) - $1.90, ISL6556BCB (SOIC) - $1.90, ISL6556BCR (QFN) - $1.95 About Intersil
Intersil Corporation is a global semiconductor leader in the design and manufacture of high performance analog and wireless networking solutions. Intersil’s product portfolios address four fast growing markets – flat panel displays, optical storage (CD and DVD recordable), power management and wireless networking. Intersil brings added customer value in providing complete silicon, software and reference design solutions to new products that enhance the computing experience for people wherever they live, work or travel. For more information about Intersil or to find out how to become a member of our winning team, visit the company's web site and career page at: www.intersil.com

Endura and Dynamic VID are trademarks of Intersil Americas Inc.
All other trademarks mentioned are the property of their respective owners.