Features Accurately senses die temperature of 4 remote ICs or diode junctions and local temperature TruTherm BJT beta compensation technology accurately senses sub-micron process thermal diodes Programmable digital filters and analog front end filter 0.125°C LSb temperature resolution 0.03125°C LSb remote temperature resolution with digital filter enabled +127.875°C/–128°C and 0°C/255°C remote ranges Remote diode fault detection, model selection and offset correction Mask and status register support 3 programmable ^TCRIT outputs with programmable shared hysteresis and Fault-Queue Programmable conversion rate and shutdown mode one-shot conversion control SMBus 2.0 compatible interface, supports TIMEOUT Three-level address pin 14-pin LLP package Description LM95234 is an 11-bit digital temperature sensor with a 2-wire System Management Bus (SMBus) interface that can very accurately monitor the temperature of four remote diodes as well as its own temperature that includes patent pending remote diode TruTherm BJT beta compensation beta compensation technology. The four remote diodes can be external devices such as microprocessors, graphics processors or diode-connected 2N3904s. The LM95234's TruTherm BJT beta compensation technology allows sensing of 90 nm or 65 nm process thermal diodes accurately. The LM95234 reports temperature in two different formats for +127.875°C/–128°C range and 0°C/255°C range. The LM95234 ^TCRIT1, ^TCRIT2 and ^TCRIT3 outputs are triggered when any unmasked channel exceeds its corresponding programmable limit and can be used to shutdown the system, to turn on the system fans or as a microcontroller interrupt function. The current status of the ^TCRIT1, ^TCRIT2 and ^TCRIT3 pins can be read back from the status registers. Mask registers are available for further control of the ^TCRIT outputs. Two LM95234 remote temperature channels have programmable digital filters while the other two remote channels utilize a fault-queue to minimize unwanted ^TCRIT events when temperature spikes are encountered. For optimum flexibility and accuracy, each LM95234 channel includes registers for sub-micron process or 2N3904 diode model selection as well as offset correction. A three-level address pin allows connection of up to 3 LM95234s to the same SMBus master. The LM95234 includes power saving functions such as: programmable conversion rate, shutdown mode, and disabling of unused channels. Key Specification ■  Local Temperature Accuracy ±2.0°C (max) ■  Remote Diode Temperature Accuracy ±0.875°C (max) ■  Supply Voltage 3.0V to 3.6V ■  Average Supply Current    (1Hz conversion rate) 0.57 mA (typ) Applications Processor/Computer System Thermal Management   (e.g. Laptop, Desktop, Workstations, Server) Electronic Test Equipment Office Electronics

Typical Application click for larger image
Typical Performance *click for larger image Thermal Diode Performance Comparison

Parameters Values Remote Diode Thermal Sensors 4 Temperature Accuracy (+/-) 0.875 deg C Supply Min 3.0 Volt Quiescent Current 0.57 mA Temperature Min -40 deg C Temperature Max 140 deg C Interface Type 2-Wire Serial Programmable Setpoints Yes TruTherm(TM) Beta Compensation Yes Resolution 13 bits Resolution degC/LSB 0.03125 Supply Max 3.6 Volt Shut down Yes Interrupt Outputs 3 Fault Queue Yes Automotive Yes PowerWise Yes

Datasheets

Title		Size	Date	Other Language
	LM95234 Quad Remote Diode and Local Temperature Sensor with SMBus Interface and TruTherm™ Technology	849 Kbytes	27-Jun-07

Part Number(s) (NSID)	Top View	Availability	Current Reported Stock	Budgetary Pricing	Pack Size
LM95234CISD/NOPB LM95234CISD RoHS Status	LLP	Full production Lead Time: 6 weeks	Distributor Region Qty ARROW Worldwide 806 CEAC Asia Pacific 4000 DIGI-KEY Worldwide 9289 FARNELL Europe and Asia 1244 MOUSER Worldwide 840 NEWARK Americas 349 TAYLOR Americas 806	$1.08 each at 1K+ pcs	reel of 1000
LM95234CISDX/NOPB LM95234CISDX RoHS Status	LLP	Full production Lead Time: 8 weeks	Distributor Region Qty DIGI-KEY Worldwide 0	$1.08 each at 1K+ pcs	reel of 4500

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 LM95234.

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 LM95234 is located at RoHS Status.

Part Number(s) (NSID)	Description	Availability	Current Reported Stock	Budgetary Pricing	Pack Size
LM95234EB/NOPB	Quad Remote Diode and Local Temperature Sensor with SMBus Interface and TruThermTM Technology from the PowerWise® Family	Full production Lead Free (RoHS)	Distributor Region Qty DIGI-KEY Worldwide 0	$140.00 each	1
Description: The LM95234EB features an 11-bit digital temperature sensor with a 2-wire System Management Bus (SMBus) interface that can very accurately monitor the temperatue of four remote diodes as well as its own temperature that includes TruThermTM BJT beta compensation technology. The LM95234EB is designed to ease the evaluation and design-in of National Semiconductors LM95234 remote diode and local digital temperature sensor. The LM95234EB board connects via USB to a PC and is controlled by the SensorEval software, which is included with the board. SensorEval software allows easy access and control of the LM95234's registers. The LM95234EB board is powered through the USB connection and no other external power sources are required. Features: Accurately senses die temperature of 4 remote ICs or diode junctions and the local temperature TruTherm BJT beta compensation technology accurately senses sub-micron process thermal diodes 0.125°C LSB temperature resolution 0.03125°C LSB remote temperature resolution with digital filter enabled +127.875?C/-128°C and 0°C/255°C remote ranges Programmable digital filters and analog front end filter Remote diode fault detection, model selection, and offset correction Mask and status register support 3 programmable TCRIT outputs with programmable hysteresis SMBus 2.0 compatible interface, supports TIMEOUT Programmable conversion rate and shutdown mode one-shot conversion control Three-level address pin 14-pin LLP package Contents: Fully assembled LM95234 Evaluation Board SensorEval Software CD LM95234 Evaluation Board User's Guide

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
LM95234CISD/NOPB LM95234CISD	40.451 40.603	LLP	14	1 1	260 260	Detail	Download	N/A	NS UZXYTT 95234CI
LM95234CISDX/NOPB LM95234CISDX	40.451 40.603	LLP	14	1 1	260 260	Detail	Download	N/A	NS UZXYTT 95234CI

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 LM95234.

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 LM95234 is located at RoHS Status.

CAD Symbols and Models Download LM95234 CAD Symbols

Models N/A

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM95234CISD	CMOS7	0	21301	0	0	1584000	3	449464325
LM95234CISDX	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 LM95234.

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 LM95234 is located at RoHS Status.