Features 8-bit ΣΔ ADC Monitors 16 power supplies Monitors 4 remote thermal diodes and 2 LM60 New TruTherm technology support for precision thermal diode measurements Internal ambient temperature sensing Programmable autonomous fan control based on temperature readings with fan boost support Fan boost support on tachometer limit error event Fan control based on 13-step lookup table or PI Control Loop or combination of both PI fan control loop supports Tcontrol Temperature reading digital filters 0.5°C digital temperature sensor resolution 0.0625°C filtered temperature resolution for fan control 2 PWM fan speed control outputs 4 fan tachometer inputs Dual processor thermal throttling ( ^PROCHOT) monitoring Dual dynamic VID monitoring (6/7 VIDs per processor) supports VRD10.2/11 8 general purpose I/Os: 4 can be configured as fan tachometer inputs 2 can be configured to connect to processor ^THERMTRIP 2 are standard GPIOs that could be used to monitor ^IERR signal 2 general purpose inputs that can be used to monitor the 7th VID signal for VRD11 Limit register comparisons of all monitored values 2-wire serial digital interface, SMBus 2.0 compliant Supports byte/block read and write Selectable slave address (tri-level pin selects 1 of 3 possible addresses) ^ALERT output supports interrupt or comparator modes 2.5V reference voltage output 56-pin TSSOP package XOR-tree test mode Description The LM94 hardware monitor has a two wire digital interface compatible with SMBus 2.0. Using a ΣΔ ADC, the LM94 measures the temperature of four remote diode connected transistors as well as its own die and 16 power supply voltages. The LM94 has new TruTherm technology that supports precision thermal diode measurements of processors on sub-micron processes. To set fan speed, the LM94 has two PWM outputs that are each controlled by up to six temperature zones. The fan-control algorithm can be based on a lookup table, PI (proportional/integral) control loop, or a combination of both. The LM94 includes digital filters that can be invoked to smooth temperature readings for better control of fan speed such that acoustical noise is minimized. The LM94 has four tachometer inputs to measure fan speed. Limit and status registers for all measured values are included. The LM94 builds upon the functionality of previous motherboard server management ASICs, such as the LM93. It also adds measurement and control support for dynamic Vccp monitoring for VRD10/11 and ^PROCHOT. It is designed to monitor a dual processor Xeon class motherboard with a minimum of external components. Key Specification Voltage Measurement Accuracy ±2% FS (max) Temperature Resolution 9-bits, 0.5°C Temperature Sensor Accuracy ±2.5 °C (max) Temperature Range: LM94 Operational 0°C to +85°C Remote Temp Accuracy 0°C to +125°C Power Supply Voltage +3.0V to +3.6V Power Supply Current 1.6 mA Applications Servers Workstations Multi-processor based equipment

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

Datasheets

Title		Size	Date	Other Language
	LM94 Hardware Monitor with PI Loop Fan Control for Server Management	2104 Kbytes	15-Jul-10

Other Technical Documents

Title		Type	Date
	TruTherm Technology Presentation	App Note	2006-05-23

Part Number(s) (NSID)	Top View	Availability	Current Reported Stock	Budgetary Pricing	Pack Size
LM94CIMT/NOPB LM94CIMT RoHS Status	TSSOP	Full production Lead Time: 6 weeks	Distributor Region Qty AVNET-EM Worldwide 136 DIGI-KEY Worldwide 538 RS COMPONENTS Worldwide 32	$6.20 each at 1K+ pcs	rail of 34
LM94CIMTX/NOPB LM94CIMTX RoHS Status	TSSOP	Full production Lead Time: 6 weeks	Distributor Region Qty DIGI-KEY Worldwide 0	$6.20 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 LM94.

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 LM94 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
LM94CIMT/NOPB LM94CIMT	222.11 223	TSSOP	56	2 2	260 235	Detail	Download	N/A	NSUZXYTTE# LM94CIMT
LM94CIMTX/NOPB LM94CIMTX	222.11 223	TSSOP	56	2 2	260 235	Detail	Download	N/A	NSUZXYTTE# LM94CIMT

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 LM94.

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 LM94 is located at RoHS Status.

CAD Symbols and Models Download LM94 CAD Symbols

Models N/A

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM94CIMT	CMOS7	0	21301	0	0	1584000	3	449464325
LM94CIMTX	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 LM94.

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 LM94 is located at RoHS Status.