Features • Window comparison simplifies design of ACPI compatible temperature monitoring and control. • Serial Bus interface • Separate open-drain outputs for Interrupt and Critical Temperature shutdown • Shutdown mode to minimize power consumption • Up to 4 LM76s can be connected to a single bus • 12-bit + sign output; full-scale reading of over 127°C Description The LM76 is a digital temperature sensor and thermal window comparator with an I2C™ Serial Bus interface with an accuracy of ±1°C. This accuracy for the LM76CHM is specified for a -10°C to 45°C temperature range, while for the LM76CNM the temperature range is 70°C to 100°C. The LM76CHM is specified with an accuracy ±0.5°C at 25°C. The window-comparator architecture of the LM76 eases the design of temperature control systems conforming to the ACPI (Advanced Configuration and Power Interface) specification for personal computers. The open-drain Interrupt (INT) output becomes active whenever temperature goes outside a programmable window, while a separate Critical Temperature Alarm (T_CRIT_A) output becomes active when the temperature exceeds a programmable critical limit. The INT output can operate in either a comparator or event mode, while the T_CRIT_A output operates in comparator mode only. The host can program both the upper and lower limits of the window as well as the critical temperature limit. Programmable hysterisis as well as a fault queue are available to minimize false tripping. Two pins (A0, A1) are available for address selection. The sensor powers up with default thresholds of 2°C THYST, 10°C TLOW, 64°C THIGH, and 80°C T_CRIT. The LM76's 3.3V and 5.0V supply voltage, Serial Bus interface, 12-bit + sign output, and full-scale range of over 127°C make it ideal for a wide range of applications. These include thermal management and protection applications in personal computers, electronic test equipment, office electronics and bio-medical applications. Key Specification Supply Voltage   3.3V or 5.0V Supply Current operating 250 µA (typ)     450 µA (max)   shutdown 8 µA (max) Temperature Accuracy +25°C ±0.5°C(max)   -10°C to +45°C ±1.0°C(max)   70°C to 100°C ±1.0°C(max) Resolution   0.0625°C Applications • System Thermal Management • Personal Computers • Office Electronics • HVAC

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Datasheets

Title		Size	Date	Other Language
	LM76 ±0.5°C, ±1°C, 12-Bit + Sign Digital Temperature Sensor and Thermal Window Comparator with Two-Wire Interface	351 Kbytes	20-Nov-03	日本語

More Application Notes

Title		Size	Date	Other Language
	AN-1155: Application Note 1155 A Simple Software I2C Routine for the COP8	82 Kbytes	15-May-04
	AN-1256: Application Note 1256 Tiny Temperature Sensors for Portable Systems	66 Kbytes	1-Oct-02

Part Number(s) (NSID)	Top View	Availability	Current Reported Stock	Budgetary Pricing	Standard Pack Size
LM76CHM-5/NOPB LM76CHM-5 RoHS Status	SOIC NARROW	Full production Lead Time: 12 weeks	Distributor Region Qty AVNET-EM Worldwide 3 DIGIKEY Worldwide 0 NEWARK Americas 55 RS COMPONENTS Worldwide 63	$1.17 each at 1K+ pcs	rail of 95
LM76CHMX-5/NOPB LM76CHMX-5 RoHS Status	SOIC NARROW	Full production Lead Time: 8 weeks	Distributor Region Qty AVNET-EM Worldwide 2500 DIGIKEY Worldwide 0	$1.17 each at 1K+ pcs	reel of 2500

Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM76CNM-3	NONE	NONE	03 Dec 2002
LM76CNMX-3	NONE	NONE	03 Dec 2002

All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/packaging/leadfree.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/quality/green.

National's certificate of product compliance is located at RoHS Status.

Part Number(s) (NSID)	Top View	Type	Pins	MSL Rating	Peak Reflow	RoHS Status	CAD Symbols	Models	Package Marking Format
LM76CHM-5/NOPB LM76CHM-5		SOIC NARROW	8	1 1	260 235	Detail	Download	N/A	NSZXTT LM76 CHM-5
LM76CHMX-5/NOPB LM76CHMX-5		SOIC NARROW	8	1 1	260 235	Detail	Download	N/A	NSZXTT LM76 CHM-5

All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/packaging/leadfree.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/quality/green.

National's certificate of product compliance is located at RoHS Status.

Design Tools

Title	Size	Date
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

CAD Symbols and Models Download LM76 CAD Symbols

Models N/A

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM76CHM-5	CS065	2	38968	52	0	4402000	1	1249079519
LM76CHMX-5	CS065	2	38968	52	0	4402000	1	1249079519

Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR. The Long Term Failure Rates were calculated at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress temperature of 150°C to an application temperature of 55°C.

For more information on Reliability Metrics, please click here.

All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/packaging/leadfree.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/quality/green.

National's certificate of product compliance is located at RoHS Status.

Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM76CNM-3	NONE	NONE	03 Dec 2002
LM76CNMX-3	NONE	NONE	03 Dec 2002