LM79 - Microprocessor System Hardware Monitor [Obsolete]
Datasheet Obsolete Versions Design Tools Application Notes Knowledge Base

Features
Temperature sensing
5 positive voltage inputs
2 op amps for negative voltage monitoring
3 fan speed monitoring inputs
Input for additional temperature sensors
Chassis Intrusion Detector input
WATCHDOG comparison of all monitored values
POST code storage RAM
ISA and I2C™ Serial Bus interfaces

Key Specification


Voltage monitoring accuracy ±1% (max)
Temperature Accuracy -10°C to +100°C ±3°C (max)
Supply Voltage 5V
Supply CurrentOperating:1 mA typ
 Shutdown:10 µA typ
ADC Resolution 8 Bits

 

General Description


The LM79 is a highly integrated Data Acquisition system for hardware monitoring of servers, Personal Computers, or virtually any microprocessor based system. More...


Applications


System Hardware Monitoring for Servers and PCs
Office Electronics
Electronic Test Equipment and Instrumentation

Also Recommended


LM80Max Output 0-2.56V (Next Generation)
LM87Additional 2 Sets Remote Diode Sensing
LM81Additional DAC Output For Fan Speed Control
Additional Resources
Design Tools

Application Notes



Datasheet
RoHS Compliance Information Size in KbytesDate Click link below to Download
LM79 Microprocessor System Hardware Monitor 481
Kbytes
26-Feb-01 Download
LM79 Microprocessor System Hardware Monitor (Japanese)
573 Kbytes   Download

If you have trouble printing or viewing PDF file(s), see Printing Problems.

Obsolete Versions

Obsolete PartAlternate Part or SupplierSourceLast Time Buy Date
LM79CCVF
NONE
NONE
03 Dec 2002
LM79CCVFX
NONE
NONE
03 Dec 2002
LM79L05AC MDA
NONE
NATIONAL SEMICONDUCTOR
03 Dec 2008
LM79L05AC MWA
NONE
NATIONAL SEMICONDUCTOR
03 Dec 2008
LM79L15ACZ
LM337LZ
NATIONAL SEMICONDUCTOR
01 Dec 2009
LM79M05C MWC
NONE
NATIONAL SEMICONDUCTOR
03 Dec 2008
LM79M05CT
LM337T
NATIONAL SEMICONDUCTOR
01 Dec 2009
LM79M15CT
LM337T
NATIONAL SEMICONDUCTOR
01 Dec 2009

General Description


The LM79 is a highly integrated Data Acquisition system for hardware monitoring of servers, Personal Computers, or virtually any microprocessor based system. In a PC, the LM79 can be used to monitor power supply voltages, temperatures, and fan speeds. Actual values for these inputs can be read at any time, and programmable WATCHDOG limits in the LM79 activate a fully programmable and maskable interrupt system with two outputs.

The LM79 has an on-chip temperature sensor, 5 positive analog inputs, two inverting inputs (for monitoring negative voltages), and an 8-bit ADC. An input is provided for the overtemperature outputs of additional temperature sensors and this is linked to the interrupt system. The LM79 provides inputs for three fan tachometer outputs. Additional inputs are provided for Chassis Intrusion detection circuits, 5 VID monitor inputs, and chainable interrupt. The LM79 provides both ISA and Serial Bus interfaces. A 32-byte auto-increment RAM is provided for POST (Power On Self Test) code storage.

Compared to the LM78, the LM79 has the following differences:

  • an additional VID input pin
  • an additional register for device identification
  • open drain Power Switch Bypass# Output

Design Tools


TitleSize in Kbytes Date Click link below to Download    
LMxx - Windows 95/98 VXD drivers with stand alone application for talking to temperature sensors or hardware monitors on a mother board 1366 Kbytes 28-Jul-2003 View Download  

If you have trouble printing or viewing PDF file(s), see Printing Problems.

More Application Notes


TitleSize in Kbytes Date Click link below to Download
AN-1155: Application Note 1155 A Simple Software I2C Routine for the COP8 82
Kbytes
15-May-04 Download
AN-1256: Application Note 1256 Tiny Temperature Sensors for Portable Systems 66
Kbytes
1-Oct-02 Download

If you have trouble printing or viewing PDF file(s), see Printing Problems.

[Information as of 8-Nov-2009]