Features Accurately senses the temperature of remote diodes Offset register allows use of a variety of thermal diodes 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 MSOP package Description The LM99 is an 11-bit remote diode temperature sensor with a 2-wire System Management Bus (SMBus) serial interface. The LM99 accurately measures: (1) its own temperature and (2) the temperature of a remote diode-connected transistor such as the 2N3904 or a thermal diode commonly found on Graphics Processor Units (GPU), Computer Processor Units (CPU or other ASICs. The LM99 remote diode temperature sensor shifts the temperature from the remote sensor down 16°C and operates on that shifted temperature: The local temperature reading requires no offset. The LM99 has an Offset Register which provides a means for precise matching to various thermal diodes. Contact hardware.monitor@nsc.com for the latest details. The LM99 and LM99-1 have the same functions but different SMBus slave addresses. This allows for one of each to be on the same bus at the same time. 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. Key Specification Supply Voltage 3.0 V to 3.6 V Supply Current 0.8 mA (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 to 50°C, TD= 120°C to 140°C ±1.0°C (max) TA= 0°C to 85°C, TD= 25°C to 140°C ±3.0°C (max) Applications Graphics Processor Thermal Management Computer Processor Thermal Management Electronic Test Equipment Office Electronics

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

Parameters Values Remote Diode Thermal Sensors 1 Temperature Accuracy (+/-) 1 deg C Supply Min 3 Volt Quiescent Current 1.7 mA Temperature Min 30 deg C Temperature Max 140 deg C Interface Type SMBus Programmable Setpoints Yes Resolution 11 bits Resolution degC/LSB 0.125 Supply Max 3.6 Volt Shut down Yes Interrupt Outputs 2 Fault Queue Yes PowerWise Yes

Datasheets

Title		Size	Date	Other Language
	LM99 ±1°C Accurate, Remote Diode and Local Digital Temperature Sensor with Two-Wire Interface	349 Kbytes	16-Jul-03

Part Number(s) (NSID)	Top View	Availability	Current Reported Stock	Budgetary Pricing	Pack Size
LM99-1CIMM/NOPB LM99-1CIMM RoHS Status	MINI SOIC	Full production Lead Time: 6 weeks	Distributor Region Qty DIGI-KEY Worldwide 0 RS COMPONENTS Worldwide 75	$1.10 each at 1K+ pcs	reel of 1000
LM99CIMM/NOPB LM99CIMM RoHS Status	MINI SOIC	Full production Lead Time: 6 weeks	Distributor Region Qty ARROW Worldwide 1000 DIGI-KEY Worldwide 0 FARNELL Europe and Asia 876 MOUSER Worldwide 960 NEWARK Americas 802 RS COMPONENTS Worldwide 75 TAYLOR Americas 1000	$1.10 each at 1K+ pcs	reel of 1000

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 LM99.

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 LM99 is located at RoHS Status.

Part Number(s) (NSID)	Description	Availability	Current Reported Stock	Budgetary Pricing	Pack Size
LM99-1EVAL	LM99-1EVAL Evaluation Board	Full production	Distributor Region Qty DIGI-KEY Worldwide 0	$78.00 each	1

Part Number(s) (NSID)	Description	Availability	Current Reported Stock	Budgetary Pricing	Pack Size
LM99EVAL	LM99EVAL Evaluation Board	Full production	Distributor Region Qty DIGI-KEY Worldwide 0 TAYLOR Americas 5	$78.00 each	1

National Semiconductor follows the provisions of the Product Stewardship Guide for Customers (CSP-9-111C1) and Banned Substances and Materials of Interest Specification (CSP-9-111S2) for regulatory environmental compliance. Details may be found at: www.national.com/en/packaging/greennopb.html. Lead free products are RoHS compliant.

Lead Free product status is available through the search tool located here

Part Number(s) (NSID)	Weight (milligrams)	Type	Pins	MSL Rating	Peak Reflow	RoHS Status	CAD Symbols	Models	Package Marking Format
LM99-1CIMM/NOPB LM99-1CIMM	29.851 30.002	MINI SOIC	8	1 1	260 260	Detail	Download	N/A	ZXTT T20C
LM99CIMM/NOPB LM99CIMM	29.851 30.002	MINI SOIC	8	1 1	260 260	Detail	Download	N/A	ZXTT T17C

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 LM99.

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 LM99 is located at RoHS Status.

Design Tools

Title	Size	Date
SensorEval Software for Thermal Mangement Products

CAD Symbols and Models Download LM99 CAD Symbols

Models N/A

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM99-1CIMM	CMOS7	0	21301	0	0	1584000	3	449464325
LM99CIMM	CMOS7	0	21301	0	0	1584000	3	449464325

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 LM99.

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 LM99 is located at RoHS Status.