1FEATURES
23• Accurately Senses Die Temperature of Remote
ICs or Diode Junctions
• Offset Register Allows Sensing a Variety of
Thermal Diodes Accurately
• On-Board Local Temperature Sensing
• 10-Bit Plus Sign Remote Diode Temperature
Data Format, 0.125°C Resolution
• T_CRIT_A Output Useful for System Shutdown
• ALERT Output Supports SMBus 2.0 Protocol
• SMBus 2.0 Compatible Interface, Supports
TIMEOUT
• 8-Pin VSSOP and SOIC Packages

APPLICATIONS
• Computer System Thermal Management
(For Example, Laptop, Desktop, Workstations,
Server)
• Electronic Test Equipment
• Office Electronics

KEY SPECIFICATIONS
• Supply Voltage 3.0V to 3.6V
• Supply Current 0.8mA (typ)
• Local Temp Accuracy (includes quantization
error)
– TA=25°C to 125°C, ±3.0°C (max)
• Remote Diode Temp Accuracy (includes
quantization error)
– TA=30°C, TD=80°C, ±0.75°C (max)
– TA=30°C to 50°C, TD=60°C to 100°C, ±1.0°C
(max)
– TA=0°C to 85°C, TD=25°C to 125°C, ±3.0°C
(max)

DESCRIPTION
The LM86 is an 11-bit digital temperature sensor with
a 2-wire System Management Bus (SMBus) serial
interface. The LM86 accurately measures its own
temperature as well as the temperature of an external
device, such as processor thermal diode or diode
connected transistor such as the 2N3904. The
temperature of any ASIC can be accurately
determined using the LM86 as long as a dedicated
diode (semiconductor junction) is available on the
target die. The LM86 remote sensor accuracy of
±0.75°C is factory trimmed for the 1.008 typical
nonideality factor of the mobile Pentium™ III thermal
diode. The LM86 has an Offset register to allow measuring other diodes without requiring continuous
software management. Contact
hardware.monitor.team@nsc.com to obtain the latest
data for new processors.
Activation of the ALERT output occurs when any
temperature goes outside a preprogrammed window
set by the HIGH and LOW temperature limit registers
or exceeds the T_CRIT temperature limit. Activation
of the T_CRIT_A occurs when any temperature
exceeds the T_CRIT programmed limit. The LM86 is
pin and register compatible with the the Analog
Devices ADM1032 and Maxim MAX6657/8.