Document
LM93 Hardware Monitor with Integrated Fan Control for Server Management
April 2004
LM93 Hardware Monitor with Integrated Fan Control for Server Management
1.0 General Description
The LM93, hardware monitor, has a two wire digital interface compatible with SMBus 2.0. Using an 8-bit Σ∆ ADC, the LM93 measures the temperature of two remote diode connected transistors as well as its own die and 16 power supply voltages. To set fan speed, the LM93 has two PWM outputs that are each controlled by up to four temperature zones. The fancontrol algorithm is lookup table based. The LM93 includes a digital filter that can be invoked to smooth temperature readings for better control of fan speed. The LM93 has four tachometer inputs to measure fan speed. Limit and status registers for all measured values are included. The LM93 builds upon the functionality of previous motherboard management ASICs and uses some of the LM85’s features (i.e. smart tachometer mode). It also adds measurement and control support for dynamic Vccp monitoring and PROCHOT. It is designed to monitor a dual processor Xeon class motherboard with a minimum of external components. n Dual dynamic VID monitoring (6 VIDs per processor) n 8 general purpose I/Os: — 4 can be configured as fan tachometer inputs — 2 can be configured to connect to THERMTRIP from a processor — 2 are standard GPIOs that could be used to monitor IERR signal n 2 general purpose inputs that can be used to monitor SCSI termination signals n Limit register comparisons of all monitored values n 2-wire, SMBus 2.0 compliant, serial digital interface — Supports byte/block read and write — Configurable slave address (tri-level pin selects 1 of 3 possible addresses) n 2.5V reference voltage output n 56-pin TSSOP package n XOR-tree test mode
3.0 Key Specifications
Voltage Measurement Accuracy Resolution Temperature Sensor Accuracy Temperature Range: — LM93 Operational — Remote Temp Accuracy n Power Supply Voltage n Power Supply Current n n n n
± 2% FS (max)
8-bits, 1˚C
2.0 Features
n n n n n n n n n n n n 8-bit Σ∆ ADC Monitors 16 power supplies Monitors 2 remote thermal diodes Internal ambient temperature sensing Programmable autonomous fan control based on temperature readings with fan boost support Fan control based on 13-step lookup table Temperature reading digital filter 1.0˚C digital temperature sensor resolution 0.5˚C temperature resolution for fan control 2 PWM fan speed control outputs 4 fan tachometer inputs Dual processor thermal throttling (PROCHOT) monitoring
± 3˚C (max)
0˚C to +85˚C 0˚C to +125˚C +3.0V to +3.6V 0.9 mA
4.0 Applications
n Servers n Workstations n Multi-Microprocessor based equipment
5.0 Ordering Information
Order Number NS Package Number Transport media LM93CIMT LM93CIMTX MTD56 MTD56 34 units in rail 1000 units in tape-and-reel
I2C is a registered trademark of the Philips Corporation.
© 2004 National Semiconductor Corporation
DS200682
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LM93
6.0 Block Diagram
20068201
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LM93
7.0 Application
Baseboard management of a Dual processor server. Two LM93s may be required to manage a quad processor base-
board. The block diagram of LM93 hardware is illustrated below. The hardware implementation is a single chip ASIC solution.
2 Way Xeon Server Management
20068205
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LM93
Table of Contents
1.0 General Description ..................................................................................................................................... 1 2.0 Features ....................................................................................................................................................... 1 3.0 Key Specifications ........................................................................................................................................ 1 4.0 Applications .................................................................................................................................................. 1 5.0 Ordering Information .................................................................................................................................... 1 6.0 Block Diagram .............................................................................................................................................. 2 7.0 Application .................................................................................................................................................... 3 8.0 Connection Diagram .................................................................................................................................... 7 9.0 Pin Descriptions ........................................................................................................................................... 8 10.0 Server Terminology .................................................................................................................................. 10 11.0 Recommended I.