ADT7460 Datasheet, PDF (1/48 Pages) Analog Devices – dB COOL Remote Thermal Controller and Fan Controller

a
dBCOOL^™ Remote Thermal
Controller and Fan Controller
ADT7460^*
FEATURES
Controls and Monitors up to 4 Fan Speeds
1 On-Chip and 2 Remote Temperature Sensors
Dynamic T_MIN Control Mode Optimizes System Acoustics
Intelligently
Automatic Fan Speed Control Mode Controls System
Cooling Based on Measured Temperature
Enhanced Acoustic Mode Dramatically Reduces User
Perception of Changing Fan Speeds
Thermal Protection Feature via THERM Output
Monitors Performance Impact of Intel^® Pentium^® 4
Processor Thermal Control Circuit via THERM Input
2-Wire and 3-Wire Fan Speed Measurement
Limit Comparison of All Monitored Values
Meets SMBus 2.0 Electrical Specifications
(Fully SMBus 1.1 Compliant)
APPLICATIONS
Low Acoustic Noise PCs
Networking and Telecommunications Equipment
GENERAL DESCRIPTION
The ADT7460 dBCOOL controller is a thermal monitor and
multiple PWM fan controller for noise-sensitive applications
requiring active system cooling. It can monitor the temperature
of up to two remote sensor diodes, plus its own internal tem-
perature. It can measure and control the speed of up to four
fans so that they operate at the lowest possible speed for mini-
mum acoustic noise. The Automatic Fan Speed Control Loop
optimizes fan speed for a given temperature. A unique Dynamic
T_MIN Control Mode enables the system thermals/acoustics
to be intelligently managed. The effectiveness of the system’s
thermal solution can be monitored using the THERM input.
The ADT7460 also provides critical Thermal Protection to the
system using the bidirectional THERM pin as an output to
prevent system or component overheating.
FUNCTIONAL BLOCK DIAGRAM
ADDR
SELECT ADDR EN SCL SDA SMBALERT
PWM1
PWM2
PWM3
TACH1
TACH2
TACH3
TACH4
THERM
V_CC
D1+
D1–
D2+
D2–
+2.5V_IN
PWM
REGISTERS
AND
CONTROLLERS
V_CC TO ADT7460
BAND GAP
TEMP. SENSOR
ACOUSTIC
ENHANCEMENT
CONTROL
FAN SPEED
COUNTER
PERFORMANCE
MONITORING
SMBUS
ADDRESS
SELECTION
SERIAL BUS
INTERFACE
AUTOMATIC
FAN SPEED
CONTROL
ADDRESS
POINTER
REGISTER
DYNAMIC
T_MIN
CONTROL
PWM
CONFIGURATION
REGISTERS
INTERRUPT
MASKING
THERMAL
PROTECTION
ADT7460
INPUT
SIGNAL
CONDITIONING
AND
ANALOG
MULTIPLEXER
10-BIT
ADC
BAND GAP
REFERENCE
GND
INTERRUPT
STATUS
REGISTERS
LIMIT
COMPARATORS
VALUE AND
LIMIT
REGISTERS
*Protected by U.S. Patent Nos. 6,188,189; 6,169,442; 6,097,239; 5,982,221; and 5,867,012. Other patents pending.
dBCOOL is a trademark of Analog Devices, Inc.
Intel and Pentium are registered trademarks of Intel Corp.
REV. 0
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its use,
nor for any infringements of patents or other rights of third parties that may
result from its use. No license is granted by implication or otherwise under any
patent or patent rights of Analog Devices.
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© Analog Devices, Inc., 2002