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National Semiconductor Introduces Analog-Optimized SensorPath Bus for Smart Motherboard Design

Next Generation Open-standard Bus Intelligently Repartitions Hardware Monitoring Functions on PC Motherboards; New Products Support Standard

Sep 15, 2003

INTEL DEVELOPER FORUM, SAN JOSE, CA - September 15, 2003 - National Semiconductor Corporation (NYSE:NSM) today introduced a new bus design that changes the way a PC motherboard implements thermal management.  Using just one wire, the analog-optimized SensorPath™ bus connects the SuperI/O controller with hardware monitoring sensors, simplifying board design, easing component placement and minimizing fan noise.

National developed the SensorPath bus to bypass the trade offs of current thermal management solutions, such as difficult signal routing and high cost.  The new bus supports multiple sensor monitoring points and enables independent, centralized fan control to regulate temperatures inside the PC.  The bus was developed as an open-standard for all PC manufacturers.

"National's new SensorPath bus integrates the digital hardware monitoring into the SuperI/O thus unburdening the thermal and system sensors with digital content," said Jonathan Levy, managing director of National's Advanced PC division.  "We will see the SensorPath bus as a key element in next-generation Intel motherboard designs and expect to see its general adoption over the next two years."

"We are pleased to see National bringing its new SensorPath products to the marketplace and offering a new generation of solutions for PC acoustic and thermal management," said Mike Miskho, I/O engineering manager for Intel Corporation's desktop boards operation.

SensorPath Bus Beats Heat and Noise in PCs Better
National repartitioned the hardware monitoring functions on PC motherboards to reduce the heat and noise in PCs.  Higher clock speed processors and memory chips are raising temperatures inside PCs and servers.  Fan noise continues to be a problem.  Ever-smaller form factors will heighten the routing and thermal management challenges.  Existing solutions, which integrate digital and analog, make signal routing difficult.  Standalone solutions using SMBus are typically more expensive.

National's SensorPath bus intelligently partitions the hardware monitoring functions on the motherboard by separating the analog and digital content.  This is achieved by moving sensing capabilities to the analog-intensive slaves, and control logic and registers to the SuperI/O device.  This maximizes sensor accuracy while minimizing the cost of both devices.

New Products Support SensorPath Bus Standard
National has developed two new SuperI/O controllers and two new temperature sensors to support the new SensorPath bus standard.

The PC8374L is a SuperI/O controller optimized for desktop applications that implements all the functionality needed for Intel's Pentium® 4 PC designs.  Along with SensorPath bus support and legacy peripherals (serial, parallel, floppy disk and PS/2), the PC8374L integrates glue logic functions that eliminate the need for extra motherboard components, reducing board size and cost.

The PC87427 is a third generation Server I/O controller.  In addition to SensorPath bus support and legacy peripherals (serial, parallel, floppy disk controller and PS/2 keyboard and mouse), the PC87427 incorporates a number of unique features that benefit system designers.  For example, the PC87427 supports up to eight fans, connects two copies of BIOS (Basic Input Output System) and will automatically switch when one copy is corrupted, ensuring high server reliability.

Both the PC8374L and PC87427 are manufactured with National Semiconductor's advanced 0.18µ CMOS process at its fabrication facility in South Portland, Maine.

The LM95010 and LM96010 are new temperature sensors that interface with the SensorPath bus.  The LM96010 has two remote diode temperature inputs, voltage monitoring inputs, as well as an internal ambient temperature digitized at 10-bits with +/-3 degrees centigrade accuracy.

The LM95010 monitors local temerature and has a temperature accuracy of +/-3 degrees centigrade, four hardware programmable addresses and a power supply voltage of +3.0V to +3.6V.

The LM95010 and LM96010 are also manufactured at National's fabrication facility in South Portland, Maine.

Pricing and Availability
The PC8374L for desktops is packaged in a 128-pin QFP.  Samples are available now and production is scheduled for first quarter of 2004.  In 1,000 unit quantities, the PC8374L is priced at $2.35.

The PC87427 for servers is packaged in a 128-pin QFP.  Samples are available now and production is scheduled for October.  In 1,000 unit quantities, the PC87427 is priced at $9.75.

The new temperature sensors are also sampling now.  The LM95010, packaged in an 8-pin MSOP, will go into production in November and is $1.00 in 1,000 unit quantities.  The LM96010, packaged in a 14-pin TSSOP, will go into production in first quarter of 2004 and is $1.50 in 1,000 unit quantities.

National at Intel Developer Forum Fall 2003
National Semiconductor will demonstrate the new SensorPath bus at the Intel Developer Forum Fall 2003 in San Jose, September 16-18, in National's booth number #818.  More information on National's activities at the Intel Developer Forum can be found at http://www.national.com/events/

About National Semiconductor
National Semiconductor is the premier analog company driving the information age. Combining real-world analog and state-of-the-art digital technology, the company is focused on analog-based semiconductor products, which include stand-alone devices and subsystems in the areas of power management, imaging, display drivers, audio, amplifiers and data conversion. The company targets key markets such as wireless, displays, PCs, networks and a broad range of portable applications. With headquarters in Santa Clara, California, National reported sales of $1.67 billion for its most recent fiscal year. Additional company and product information is available on the World Wide Web at www.national.com