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