Document Outline

• LM93
  • 1.0 General Description
  • 2.0 Features
  • 3.0 Key Specifications
  • 4.0 Applications
  • 5.0 Ordering Information
  • 6.0 Block Diagram
  • 7.0 Application
  • 8.0 Connection Diagram
  • 9.0 Pin Descriptions
  • 10.0 Server Terminology
  • 11.0 Recommended Implementation
  • 12.0 Functional Description
    • 12.1 MONITORING CYCLE TIME
    • 12.2 A/D INHERENT AVERAGING
    • 12.3 TEMPERATURE MONITORING
      • 12.3.1 Temperature Data Format
      • 12.3.2 Thermal Diode Fault Status
    • 12.4 VOLTAGE MONITORING
      • Voltage vs Register Reading
    • 12.5 RECOMMENDED EXTERNAL SCALING RESISTORS FOR +12V POWER RAILS
    • 12.6 RECOMMENDED EXTERNAL SCALING CIRCUIT FOR -12V POWER INPUT
    • 12.7 DYNAMIC Vccp MONITORING USING VID
    • 12.8 VREF OUTPUT
    • 12.9 PROCHOT BACKGROUND INFORMATION
    • 12.10 PROCHOT MONITORING
    • 12.11 PROCHOT OUTPUT CONTROL
    • 12.12 FAN SPEED MEASUREMENT
    • 12.13 SMART FAN SPEED MEASUREMENT
  • 13.0 Inputs/Outputs
    • 13.1 ALERT OUTPUT
    • 13.2 RESET INPUT/OUTPUT
    • 13.3 PWM1 AND PWM2 OUTPUTS
    • 13.4 SCSI_TERMx INPUTS
    • 13.5 VRD1_HOT AND VRD2_HOT INPUTS
    • 13.6 GPIO PINS
    • 13.7 FAN TACH INPUTS
  • 14.0 SMBus Interface
    • 14.1 SMBUS ADDRESSING
    • 14.2 DIGITAL NOISE EFFECT ON SMBUS COMMUNICATION
    • 14.3 GENERAL SMBUS TIMING
    • 14.4 SMBUS ERROR SAFETY FEATURES
    • 14.5 SERIAL INTERFACE PROTOCOLS
      • 14.5.1 Address Incrementing
      • 14.5.2 Block Command Code Summary
      • 14.5.3 Write Operations
        • 14.5.3.1 Write Byte
        • 14.5.3.2 Write Word
        • 14.5.3.3 SMBus Write Block to Any Address
        • 14.5.3.4 I2C(TM) Block Write
      • 14.5.4 Read Operations
        • 14.5.4.1 Read Byte
        • 14.5.4.2 Read Word
        • 14.5.4.3 SMBus Block-Write Block-Read Process Call
        • 14.5.4.4 Simulated SMBus Block-Write Block-Read Process Call
        • 14.5.4.5 SMBus Fixed Address Block Reads
        • 14.5.4.6 I2C Block Reads
    • 14.6 READING AND WRITING 16-BIT REGISTERS
  • 15.0 Using The LM93
    • 15.1 POWER ON
    • 15.2 RESETS
    • 15.3 ADDRESS SELECTION
    • 15.4 DEVICE SETUP
    • 15.5 ROUND ROBIN VOLTAGE/TEMPERATURE CONVERSION CYCLE
    • 15.6 ERROR STATUS REGISTERS
      • 15.6.1 ASF Mode
    • 15.7 MASKING, ERROR STATUS AND ALERT
    • 15.8 LAYOUT AND GROUNDING
    • 15.9 THERMAL DIODE APPLICATION
      • 15.9.1 Accuracy Effects of Diode Non-Ideality Factor
      • 15.9.2 PCB Layout for Minimizing Noise
    • 15.10 FAN CONTROL
      • 15.10.1 Automatic Fan Control Algorithm
        • FIGURE 1. Example of the LM93 Fan Control Transfer Function. Download an excel spread sheet from www
        • Zone 1/2 (CPU1 and CPU2) Table
        • Zone 3/4 (LM93 Ambient and External Ambient) Table
      • 15.10.2 Fan Control Temperature Resolution
      • 15.10.3 Zone 1-4 to PWM1-2 Binding
      • 15.10.4 Fan Control Duty Cycles
      • 15.10.5 Alternate PWM Frequencies
      • 15.10.6 Fan Control Priorities
      • 15.10.7 PWM to 100% Conditions
      • 15.10.8 VRDx_HOT Ramp-Up/Ramp-Down
      • 15.10.9 PROCHOT Ramp-Up/Ramp-Down
      • 15.10.10 Manual PWM Override
      • 15.10.11 Fan Spin-Up Control
    • 15.11 XOR TREE TEST
  • 16.0 Registers
    • 16.1 REGISTER WARNINGS
    • 16.2 REGISTER SUMMARY TABLE
      • Register Key
    • 16.3 FACTORY REGISTERS 00h-3Fh
      • 16.3.1 Register 00hXOR Test
      • 16.3.2 Register 01hSMBus Test
      • 16.3.3 Register 3EhManufacturer ID
      • 16.3.4 Register 3FhVersion/Stepping
    • 16.4 BMC ERROR STATUS REGISTERS 40h-47h
      • 16.4.1 Register 40hB_Error Status 1
      • 16.4.2 Register 41hB_Error Status 2
      • 16.4.3 Register 42hB_Error Status 3
      • 16.4.4 Register 43hB_Error Status 4
      • 16.4.5 Register 44hB_P1_PROCHOT Error Status
      • 16.4.6 Register 45hB_P2_PROCHOT Error Status
      • 16.4.7 Register 46hB_GPI Error Status
      • 16.4.8 Register 47hB_Fan Error Status
    • 16.5 HOST ERROR STATUS REGISTERS
      • 16.5.1 Register 48hH_Error Status 1
      • 16.5.2 Register 49hH_Error Status 2
      • 16.5.3 Register 4AhH_Error Status 3
      • 16.5.4 Register 4BhH_Error Status 4
      • 16.5.5 Register 4ChH_P1_PROCHOT Error Status
      • 16.5.6 Register 4DhB_P2_PROCHOT Error Status
      • 16.5.7 Register 4EhH_GPI Error Status
      • 16.5.8 Register 4FhH_Fan Error Status
    • 16.6 VALUE REGISTERS
      • 16.6.1 Registers 50-53hUnfiltered Temperature Value Registers
      • 16.6.2 Registers 54-55hFiltered Temperature Value Registers
      • 16.6.3 Register 56-65hA/D Channel Voltage Registers
      • 16.6.4 Register 67hCurrent P1_PROCHOT
      • 16.6.5 Register 68hAverage P1_PROCHOT
      • 16.6.6 Register 69hCurrent P2_PROCHOT
      • 16.6.7 Register 6AhAverage P2_PROCHOT
      • 16.6.8 Register 6BhGPI State
      • 16.6.9 Register 6ChP1_VID
      • 16.6.10 Register 6DhP2_VID
      • 16.6.11 Register 6E-75hFan Tachometer Readings
    • 16.7 LIMIT REGISTERS
      • 16.7.1 Registers 78-7FhTemperature Limit Registers
      • 16.7.2 Registers 80-83hFan Boost Temperature Registers
      • 16.7.3 Registers 90-AFhVoltage Limit Registers
      • 16.7.4 Register B0-B1hPROCHOT User Limit Registers
      • 16.7.5 Register B2-B3hDynamic Vccp Limit Offset Registers
      • 16.7.6 Register B4-BBhFan Tach Limit Registers
    • 16.8 SETUP REGISTERS
      • 16.8.1 Register BChSpecial Function Control 1 (Voltage Hysteresis and Fan Control Filter Enable)
      • 16.8.2 Register BDhSpecial Function Control 2 (Smart Tach Mode Enable and Fan Control Temperature R
      • 16.8.3 Register BEhGPI/VID Level Control
      • 16.8.4 Register BFhPWM Ramp Control
      • 16.8.5 Register C0hFan Boost Hysteresis (Zones 1/2)
      • 16.8.6 Register C1hFan Boost Hysteresis (Zones 3/4)
      • 16.8.7 Register C2hZones 1/2 Spike Smoothing Control
      • 16.8.8 Register C3hZones 1/2 MinPWM and Hysteresis
      • 16.8.9 Register C4hZones 3/4 MinPWM and Hysteresis
      • 16.8.10 Register C5hGPO
      • 16.8.11 Register C6hPROCHOT Override
      • 16.8.12 Register C7hPROCHOT Time Interval
      • 16.8.13 Register C8hPWM1 Control 1
      • 16.8.14 Register C9hPWM1 Control 2
      • 16.8.15 Register CAhPWM1 Control 3
      • 16.8.16 Register CBhSpecial Function PWM1 Control 4
      • 16.8.17 Register CChPWM2 Control 1
      • 16.8.18 Register CDhPWM2 Control 2
      • 16.8.19 Register CEhPWM2 Control 3
      • 16.8.20 Register CFhSpecial Function PWM2 Control 4
      • 16.8.21 Register D0h-D3hZone 1 to 4 Base Temperatures
      • 16.8.22 Register D4h-DFhLookup Table Steps-Zone 1/2 and Zone 3/4 Offset Temperature
      • 16.8.23 Register E0hSpecial Function TACH to PWM Binding
      • 16.8.24 Register E2hLM93 Status Control
      • 16.8.25 Register E3hLM93 Configuration
    • 16.9 SLEEP STATE CONTROL AND MASK REGISTERS
      • 16.9.1 Register E4hSleep State Control
      • 16.9.2 Register E5hS1 GPI Mask
      • 16.9.3 Register E6hS1 Tach Mask
      • 16.9.4 Register E7hS3 GPI Mask
      • 16.9.5 Register E8hS3 Tach Mask
      • 16.9.6 Register E9hS3 Temperature/Voltage Mask
      • 16.9.7 Register EAhS4/5 GPI Mask
      • 16.9.8 Register EBhS4/5 Temperature/Voltage Mask
    • 16.10 OTHER MASK REGISTERS
      • 16.10.1 Register EChGPI Error Mask
      • 16.10.2 Register EDhMiscellaneous Error Mask
      • 16.10.3 Register EEhSpecial Function Zone 1 Adjustment Offset
      • 16.10.4 Register EFhSpecial Function Zone 2 Adjustment Offset
  • 17.0 Absolute Maximum Ratings
  • 18.0 Operating Ratings (Notes , )
  • DC Electrical Characteristics
  • AC Electrical Characteristics
  • 19.0 Data Sheet Version History
  • 20.0 Physical Dimensions