National Semiconductor?s Newest Hardware Monitor IC Increases Reliability of PC Systems

March 26, 1998 -- National Semiconductor Corporation® today announced the latest addition to its growing family of system hardware monitor ICs. The LM80, a tightly integrated monolithic data acquisition system, increases the reliability of PC systems by continuously checking key analog functions including temperature, voltage and fan speed, and many key digital system signatures.

"To prolong system life cycles and minimize downtime, system administrators have a critical need for early warnings to help identify problems prior to catastrophic conditions," noted Patricia Smith, National's director of system integrated products. "By integrating key diagnostic functions, the LM80 fills that role for the PC and server market, while reducing overall system monitoring costs. In fact, desktop diagnostics have proven to be the solution to long-term system reliability at the lowest possible cost."

National's system monitor IC gives information technology managers the capability to set hazard warning limits via WATCHDOG registers for most key analog functions within the PC/server environment. During error conditions, the IC generates interrupts based on user-defined and programmed system limits for key parameters and communicates early failure warnings via the I2C interface.

The highly integrated LM80 includes an 8-bit plus sine Delta-Sigma A/D converter for high noise immunity in any microprocessor environment.

Key features of the LM80 include:

• +/?3?C temperature accuracy (?10 degrees C to 125 degrees C)
• Two sets of user-programmable watchdog limits register for Tos (over temperature) and THYST (hysteresis). Temperature data can also be written to and read from Thot and ThotHYST setpoints
• Three interrupt modes: default, one-time, and comparator
• Temperature resolution of * degree C
• A supply voltage range from 2.8V to 5.75V
• The 10mV LSB (least significant bit) and 2.56 volt input range allow distributed temperature sensing using analog output temp sensors such as National?s LM45
• Seven voltage monitoring analog inputs
• Associated watchdog registers for each voltage input (high and low)
• Two user-programmable inputs for fan speeds ranging from 1100 rpm to 8800 rpm
• Active-high chassis security input for detection of intrusion
• Board temperature interrupt input (BTI#), for use with thermostat output temp sensors (such as National's LM56 or LM75). These temp sensors may be located in strategic positions throughout the system. National also offers an application board to facilitate quick, easy hook-up to a power supply and evaluation of its output characteristics. The board plugs into the parallel printer port for communication via the I2C interface.

Price and Availability
The LM80CIMT is priced at $4.00 in 1,000-unit quantities in a 24-lead TSSOP.

National Semiconductor Corporation, a Fortune 500 company, produces system-on-a-chip silicon solutions for the information highway, based on its leadership in analog and mixed signal technologies. National is headquartered in Santa Clara, California, and focuses on the communications, personal systems and consumer markets. National has annual sales of approximately $2.5 billion and 13,000 employees worldwide. Additional company and product information is available on the World Wide Web at www.national.com.