ADM1031ARQ-REEL7

Manufacturer Part NumberADM1031ARQ-REEL7
DescriptionIC SENSOR 2-TEMP/FAN CTRL 16QSOP
ManufacturerON Semiconductor
ADM1031ARQ-REEL7 datasheet
 


Specifications of ADM1031ARQ-REEL7

Rohs StatusRoHS non-compliantFunctionFan Control, Temp Monitor
TopologyADC, Comparator, Multiplexer, Register BankSensor TypeExternal & Internal
Sensing Temperature0°C ~ 100°C, External SensorOutput TypeSMBus™
Output AlarmYesOutput FanYes
Voltage - Supply3 V ~ 5.5 VOperating Temperature0°C ~ 100°C
Mounting TypeSurface MountPackage / Case16-QSOP
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ADM1031
Intelligent Temperature
Monitor and Dual PWM Fan
Controller
The ADM1031 is an ACPI−compliant, three−channel digital
thermometer and under/overtemperature alarm for use in personal
computers and thermal management systems. Optimized for the
Pentium
III, the part offers a 1°C higher accuracy, which allows
R
system designers to safely reduce temperature guard−banding and
increase system performance.
Two PWM fan control outputs control the speed of two cooling fans
by varying output duty cycle. Duty cycle values between 33% and
100% allow smooth control of the fans. The speed of each fan can be
monitored via TACH inputs, which can be reprogrammed as analog
inputs to allow speeds for 2−wire fans to be measured via sense
resistors. The device also detects a stalled fan. A dedicated fan speed
control loop provides control without the intervention of CPU
software. It also ensures that if the CPU or system locks up, each fan
can still be controlled based on temperature measurements, and the fan
speed is adjusted to correct any changes in system temperature. Fan
speed can also be controlled using existing ACPI software.
Two inputs (4 pins) are dedicated to remote temperature−sensing
diodes with an accuracy of ±1°C, and an on−chip temperature sensor
allows ambient temperature to be monitored. The device has a
programmable INT output to indicate error conditions, and a dedicated
FAN_FAULT output to signal fan failure. The THERM pin is a
fail−safe output for overtemperature conditions that can be used to
throttle a CPU clock.
Features
Optimized for Pentium III
Reduced Guard−banding Software
Automatic Fan Speed Control, Independent of CPU
Intervention After Initial Setup
0.125°C Resolution on External Temperature Channels
Control Loop to Minimal Acoustic Noise and Battery
Consumption
Remote Temperature Measurement Accurate to 1°C
Using Remote Diode (Two Channels)
Local Sensor with 0.25°C Resolution
Pulse Width Modulation (PWM) Fan Control for 2 Fans
Programmable PWM Frequency and PWM Duty Cycle
Tach Fan Speed Measurement (Two Channels)
Analog Input to Measure Fan Speed of 2−Wire Fans
(Using Sense Resistor)
2−Wire System Management Bus (SMBus) with ARA
Support
Applications
Notebook PCs, Network Servers, and Personal Computers
Telecommunications Equipment
© Semiconductor Components Industries, LLC, 2010
May, 2010 − Rev. 4
http://onsemi.com
MARKING DIAGRAM
1
1031A
#YYWW
xxx
= Specific Device Code
#
= Pb−Free Package
YY
= Date Code
WW
= Work Week
PIN ASSIGNMENT
PWM_OUT1
1
TACH1/AIN1
2
ADM1031
PWM_OUT2
3
TACH2/AIN2
4
GND
5
V
6
CC
THERM
7
FAN_FAULT
8
Overtemperature THERM Output Pin for CPU
Throttling
Programmable INT Output Pin
Configurable Offsets for Temperature Channels 3.0 V
to 5.5 V Supply Range
Shutdown Mode to Minimize Power Consumption
Limit Comparison of All Monitored Values
This is a Pb−Free Device
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 29 of this data sheet.
1
QSOP−16
CASE 492
RQZ
SCL
16
SDA
15
14
INT(SMBALERT)
ADD
13
D2+
12
D2–
11
D1+
10
9
D1–
Publication Order Number:
ADM1031/D

ADM1031ARQ-REEL7 Summary of contents

  • Page 1

    ADM1031 Intelligent Temperature Monitor and Dual PWM Fan Controller The ADM1031 is an ACPI−compliant, three−channel digital thermometer and under/overtemperature alarm for use in personal computers and thermal management systems. Optimized for the Pentium III, the part offers a 1°C higher ...

  • Page 2

    ADM1031 PWM PWM_OUT1 1 CONTROLLERS PWM_OUT2 3 TACH2/AIN2 4 TACH SIGNAL CONDITIONING TACH1/AIN1 2 D1+ 10 D1– 9 D2+ 12 D2– 11 BANDGAP TEMPERATURE SENSOR ABSOLUTE MAXIMUM RATINGS Parameter Positive Supply Voltage ( Voltage on Any Input or ...

  • Page 3

    PIN ASSIGNMENT Pin No. Mnemonic 1 PWM_OUT1 Digital Output, Open−Drain. Pulse width modulated output to control fan speed. Requires pullup resistor (10 kW typical). 2 TACH1/AIN1 Digital/Analog Input. Fan tachometer input to measure FAN1 fan speed. Can be reprogrammed as ...

  • Page 4

    ELECTRICAL CHARACTERISTICS Parameter OPEN−DRAIN SERIAL DATA BUS OUTPUT (SDA) Output Low Voltage High−Level Output Leakage Current SERIAL BUS DIGITAL INPUTS (SCL, SDA) Input High Voltage Input Low Voltage Hysteresis DIGITAL INPUT LOGIC ...

  • Page 5

    DXP TO GND 0 DXP –5 –10 –15 –20 1 3.3 10 LEAKAGE RESISTANCE (MW) Figure 3. Temperature Error vs. PCB Track Resistance 40mV p− ...

  • Page 6

    V = 30mV p− 20mV p−p IN –1 0 100k 1M 100M 200M 300M FREQUENCY (Hz) Figure 9. Temperature Error vs. Differential−Mode Noise Frequency 0.08 0 –0.08 –0.16 –0.24 ...

  • Page 7

    Functional Description The ADM1031 is a temperature monitor and dual PWM fan controller for microprocessor−based systems. The device communicates with the system via a serial System Management Bus (SMBus). The serial bus controller has a hardwired address pin for device ...

  • Page 8

    The number of data bytes that can be transmitted over the serial bus in a single read or write operation ...

  • Page 9

    SCL SDA START BY MASTER SERIAL BUS ADDRESS BYTE Figure 16. Writing to the Address Pointer Register Only 1 SCL SDA START BY MASTER SERIAL BUS ADDRESS BYTE Figure 17. Reading Data from ...

  • Page 10

    × BIAS D+ REMOTE SENSING D– BIAS TRANSISTOR DIODE LOW−PASS FILTER f = 65kHz C Figure 18. Signal Conditioning If a discrete transistor is used, then the collector is not grounded, and is linked ...

  • Page 11

    Try to minimize the number of copper/solder joints, which can cause thermocouple effects. Where copper/solder joints are used, make sure that they are in both the D+ and D– path and at the same temperature. Thermocouple effects should not ...

  • Page 12

    Bit 1 (Fan Fault) is set whenever a fan tach failure is detected. Once cleared, it reasserts on subsequent fan tach failures. Bit 2 and Bit 3 of Status Register 1 and Status Register 2 are the Remote 1 ...

  • Page 13

    T MIN TEMPERATURE (°C) Figure 22. PWM Duty Cycle vs. Temperature Slope (T ) RANGE Figure 23 shows how, for a given T T ...

  • Page 14

    Remote 1 temperature is measuring 70°C. The PWM duty cycle calculated by the local temperature control loop is 100% (because the temperature = T ). The PWM duty cycle MAX calculated by the Remote 1 ...

  • Page 15

    Table 7. Programming PWM Duty Cycle Decimal Value PWM Duty Cycle (0×0A) 11 (0×0B) 12 (0×0C) 13 (0×0D) 14 (0×0E) 15 (0×0F) The temperature at which the fan runs ...

  • Page 16

    Register 0y24 Local Temperature T <7:3> Local Temperature T . These bits set the MIN temperature at which the fan turns on when under auto fan speed control. T can be programmed in 4°C increments. MIN 00000 = 0°C 00001 ...

  • Page 17

    READ TEMPERATURE CALCULATE NEW PWM DUTY CYCLE IS NEW NO PWM VALUE > PREVIOUS VALUE? YES INCREMENT PREVIOUS PWM VALUE BY RAMP RATE Figure 28. Filtered Mode Algorithm The filtered mode algorithm calculates a new PWM duty cycle based on ...

  • Page 18

    Finally, Figure 32 shows how the control loop reacts to temperature with the slowest ramp rate. The ramp rate is set to 1, while all other control parameters remain the same. With the slowest ramp rate selected, it took 112 ...

  • Page 19

    Programming the Filtered Automatic Fan Speed Control Loop 1. Program a value for T . MIN 2. Program a value for the slope MAX MIN RANGE 4. Program a value for fan ...

  • Page 20

    Example 1: If the desired value for RPM feedback mode is 5000 RPM, the count to be programmed is: Count = (f × 60)/R × N Since the desired RPM value 5000 RPM, the value for count is: ...

  • Page 21

    Figure 34 shows how a 3−wire fan can be driven using PWM control. 3.3 V 10kW TYPICAL TACH TACH/AIN 3.3 V ADM1031 10kΩ TYPICAL PWM_OUT Figure 34. Interfacing the ADM1031 to a 3−Wire Fan The NDT3055L n−type MOSFET was chosen ...

  • Page 22

    CLOCK CONFIG 2 REG. BIT 2 FAN INPUT START OF FAN MONITORING MEASUREMENT CYCLE PERIOD Figure 37. Fan Speed Measurement In situations where different output drive circuits are used for fan drive, it can be desirable to invert the PWM ...

  • Page 23

    V MAX (DO NOT CONNECT 5 TYP FAN2 2−WIRE TACH FAN NDT3055L NDT3055L (N−MOS) (NMOS) 3 SENSE 3.3 V 0.01mF THERM SIGNAL TO THROTTLE CPU CLOCK 3.3 V FAN_FAULT ...

  • Page 24

    Table 13. Value Registers Address R/W 0x06 R Extended Temperature Resolution (see Table 18). 0x08 R/W Fan 1 Speed. This register contains the value of the Fan 1 tach measurement. 0x09 R/W Fan 2 Speed. This register contains the value ...

  • Page 25

    Table 15. Register 0y01 Configuration 2 Power−On Default = 7FH Bit Name R/W 0 PWM 1 En R/W 1 PWM 2 En R/W 2 TACH 1 En R/W 3 TACH 2 En R/W 4 Loc Temp En R/W 5 Remote ...

  • Page 26

    Table 18. Register 0y06 Extended Temperature Resolution Power−On Default = 00H Bit Name R/W <2:0> Remote Temp 1 R <5:3> Remote Temp 2 R <7:6> Local Temp R Table 19. Register 0y20 Fan Characteristics Register 1 Power−On Default = 5DH ...

  • Page 27

    Table 21. Register 0y22 Fan Speed Configuration Register Power−On Default = 55H Bit Name R/W <3:0> Normal/Min Spd 1 R/W <7:4> Normal/Min Spd 2 R/W Table 22. Register 0y23 Fan Filter Register Power−On Default = 50H Bit Name R/W <7> ...

  • Page 28

    Table 24. Register 0y25 Remote 1 Temp T Bit Name R/W <7:3> Remote 1 Temp T R/W MIN <2:0> Remote 1 Temp R/W T RANGE Table 25. Register 0y26 Remote 2 Temp T Bit Name R/W <7:3> Remote 2 Temp ...

  • Page 29

    ... ORDERING INFORMATION Device Order Number* ADM1031ARQZ ADM1031ARQZ−REEL ADM1031ARQZ−R7 †For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging Specifications Brochure, BRD8011/D. *These are Pb−Free packages. When this bit is 0, the local offset is added to the Local Temperature Reading. When this bit is set to 1, the local offset is subtracted from the Local Temperature Reading ...

  • Page 30

    ... Opportunity/Affirmative Action Employer. This literature is subject to all applicable copyright laws and is not for resale in any manner. PUBLICATION ORDERING INFORMATION LITERATURE FULFILLMENT: Literature Distribution Center for ON Semiconductor P.O. Box 5163, Denver, Colorado 80217 USA Phone: 303−675−2175 or 800−344−3860 Toll Free USA/Canada Fax: 303− ...