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 LM77s can be connected to a single bus 9-bit + sign output; full-scale reading of over 128°C SOP and MSOP 8-lead packages Description The LM77 is a digital temperature sensor and thermal window comparator with an I 2C ™ Serial Bus interface. The window-comparator architecture of the LM77 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 LM77's 3.0V to 5.5V supply voltage range, Serial Bus interface, 9-bit + sign output, and full-scale range of over 128°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, automotive, and HVAC applications. Key Specification ■  Supply Voltage   3.0V to 5.5V ■  Supply Current operating 250 μA (typ)     500 μA (max) shutdown 5 μA (typ) ■  Temperature Accuracy −10°C to 65°C ±1.5°C(max)   −25°C to 100°C ±2°C(max)   −55°C to 125°C ±3°C(max) Applications System Thermal Management Personal Computers Office Electronics Electronic Test Equipment Automotive HVAC

Typical Application click for larger image	Block Diagram click for larger image
Typical Performance click for larger image

Datasheets

Title		Size	Date	Other Language
	LM77 9-Bit + Sign Digital Temperature Sensor and Thermal Window Comparator with Two-Wire Interface	442 Kbytes	18-Oct-10	日本語

Application Notes

Title		Size	Date	Other Language
	AN-2113: Application Note 2113 Applying I2C Compatible Temperature Sensors in Systems with Slow Clock Edges	81 Kbytes	3-May-11

Other Technical Documents

Title		Type	Date
	Sensing and Monitoring for Control and Protection Seminar	App Note	2003-02-17
	Sensing and Monitoring for Control and Protection Seminar	App Note	2003-02-17

Part Number(s) (NSID)	Top View	Availability	Current Reported Stock	Budgetary Pricing	Pack Size
LM77CIM-3/NOPB LM77CIM-3 RoHS Status	SOIC NARROW	Full production Lead Time: 6 weeks	Distributor Region Qty ARROW Worldwide 415 AVNET-EM Worldwide 152 DIGI-KEY Worldwide 168 FARNELL Europe and Asia 445 NEWARK Americas 213 TAYLOR Americas 415	$0.86 each at 1K+ pcs	rail of 95
LM77CIM-5/NOPB LM77CIM-5 RoHS Status	SOIC NARROW	Full production Lead Time: 6 weeks	Distributor Region Qty AVNET-EM Worldwide 671 CEAC Asia Pacific 475 DIGI-KEY Worldwide 15 RS COMPONENTS Worldwide 110	$0.86 each at 1K+ pcs	rail of 95
LM77CIMM-3/NOPB LM77CIMM-3 RoHS Status	MINI SOIC	Full production Lead Time: 8 weeks	Distributor Region Qty DIGI-KEY Worldwide 2213 NEWARK Americas 970	$0.86 each at 1K+ pcs	reel of 1000
LM77CIMM-5/NOPB LM77CIMM-5 RoHS Status	MINI SOIC	Full production Lead Time: 8 weeks	Distributor Region Qty DIGI-KEY Worldwide 0	$0.86 each at 1K+ pcs	reel of 1000
LM77CIMMX-3/NOPB LM77CIMMX-3 RoHS Status	MINI SOIC	Full production Lead Time: 8 weeks	Distributor Region Qty DIGI-KEY Worldwide 0	$0.86 each at 1K+ pcs	reel of 3500
LM77CIMMX-5/NOPB LM77CIMMX-5 RoHS Status	MINI SOIC	Full production Lead Time: 6 weeks	Distributor Region Qty DIGI-KEY Worldwide 0	$0.86 each at 1K+ pcs	reel of 3500
LM77CIMX-3/NOPB LM77CIMX-3 RoHS Status	SOIC NARROW	Full production Lead Time: 6 weeks	Distributor Region Qty AVNET-EM Worldwide 2500 DIGI-KEY Worldwide 0 MOUSER Worldwide 2500 TECHMOSA Asia Pacific 37500	$0.86 each at 1K+ pcs	reel of 2500
LM77CIMX-5/NOPB LM77CIMX-5 RoHS Status	SOIC NARROW	Full production Lead Time: 6 weeks	Distributor Region Qty DIGI-KEY Worldwide 0 MOUSER Worldwide 2500	$0.86 each at 1K+ pcs	reel of 2500

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

Moisture Sensitivity Level Data for LM77.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

National's certificate of product compliance for LM77 is located at RoHS Status.

Part Number(s) (NSID)	Weight (milligrams)	Type	Pins	MSL Rating	Peak Reflow	RoHS Status	CAD Symbols	Models	Package Marking Format
LM77CIM-3/NOPB LM77CIM-3	69.761 70.001	SOIC NARROW	8	1 1	260 235	Detail	Download	N/A	NSZXTT LM77 CIM-3
LM77CIM-5/NOPB LM77CIM-5	69.761 70.001	SOIC NARROW	8	1 1	260 235	Detail	Download	N/A	NSZXTT LM77 CIM-5
LM77CIMM-3/NOPB LM77CIMM-3	29.851 30.002	MINI SOIC	8	1 1	260 260	Detail	Download	N/A	ZXTT T06C
LM77CIMM-5/NOPB LM77CIMM-5	29.851 30.002	MINI SOIC	8	1 1	260 260	Detail	Download	N/A	ZXTT T07C
LM77CIMMX-3/NOPB LM77CIMMX-3	29.851 30.002	MINI SOIC	8	1 1	260 260	Detail	Download	N/A	ZXTT T06C
LM77CIMMX-5/NOPB LM77CIMMX-5	30.002	MINI SOIC	8	1 1	260 260	Detail	Download	N/A	ZXTT T07C
LM77CIMX-3/NOPB LM77CIMX-3	69.761 70.001	SOIC NARROW	8	1 1	260 235	Detail	Download	N/A	NSZXTT LM77 CIM-3
LM77CIMX-5/NOPB LM77CIMX-5	69.761 70.001	SOIC NARROW	8	1 1	260 235	Detail	Download	N/A	NSZXTT LM77 CIM-5

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

Moisture Sensitivity Level Data for LM77.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

National's certificate of product compliance for LM77 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

CAD Symbols and Models Download LM77 CAD Symbols

Models N/A

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM77CIM-3	CS065	2	47473	43	0	5527000	1	1568301341
LM77CIM-5	CS065	2	47473	43	0	5527000	1	1568301341
LM77CIMM-3	CS065	2	47473	43	0	5527000	1	1568301341
LM77CIMM-5	CS065	2	47473	43	0	5527000	1	1568301341
LM77CIMMX-3	CS065	2	47473	43	0	5527000	1	1568301341
LM77CIMMX-5	CS065	2	47473	43	0	5527000	1	1568301341
LM77CIMX-3	CS065	2	47473	43	0	5527000	1	1568301341
LM77CIMX-5	CS065	2	47473	43	0	5527000	1	1568301341

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/en/packaging/leadfree.html.

Moisture Sensitivity Level Data for LM77.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

National's certificate of product compliance for LM77 is located at RoHS Status.