dBCOOL™ Remote Thermal
a
Controller and Voltage Monitor
ADM1027*
FEATURES
GENERAL DESCRIPTION
Monitors up to 5 Supply Voltages
The ADM1027 dBCOOL controller is a complete systems
monitor and multiple PWM fan controller for noise-sensitive
applications requiring active system cooling. It can monitor
12 V, 5 V, 2.5 V CPU supply voltage, plus its own supply volt-
age. It can monitor the temperature of up to two remote sensor
diodes, plus its own internal temperature. It can measure and
control the speed of up to four fans so that they operate at the
lowest possible speed for minimum acoustic noise. The auto-
matic fan speed control loop optimizes fan speed for a given
temperature. Once the control loop parameters are programmed,
the ADM1027 can vary fan speed without CPU intervention.
Controls and Monitors up to 4 Fan Speeds
1 On-Chip and 2 Remote Temperature Sensors
Monitors up to 5 Processor VID Bits
Automatic Fan Speed Control Mode Controls System
Cooling Based on Measured Temperature
Enhanced Acoustic Mode Dramatically Reduces User
Perception of Changing Fan Speeds
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
FUNCTIONAL BLOCK DIAGRAM
ADDR
SELECT ADDR EN
SCL SDA
SMBALERT
VID4
VID3
VID2
VID1
VID0
SMBUS
ADDRESS
SELECTION
SERIAL BUS
INTERFACE
VID
REGISTER
ADDRESS
POINTER
REGISTER
AUTOMATIC
FAN SPEED
CONTROL
PWM
CONFIGURATION
REGISTERS
PWM1
PWM2
PWM
REGISTERS
AND
ACOUSTIC
ENHANCEMENT
CONTROL
PWM3
CONTROLLERS
TACH1
TACH2
TACH3
TACH4
FAN SPEED
COUNTER
INTERRUPT
MASKING
V
CC
TO ADM1027
V
CC
ADM1027
INTERRUPT
STATUS
REGISTERS
D1+
D1–
D2+
D2–
INPUT
SIGNAL
CONDITIONING
AND
ANALOG
MULTIPLEXER
10-BIT
ADC
+5V
LIMIT
COMPARATORS
IN
IN
IN
+12V
+2.5V
V
BAND GAP
REFERENCE
CCP
VALUE AND
LIMIT
REGISTERS
BAND GAP
TEMP. SENSOR
GND
*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.
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, norforanyinfringementsofpatentsorotherrightsofthirdpartiesthat
may result from its use. No license is granted by implication or otherwise
under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
Fax: 781/326-8703
www.analog.com
© Analog Devices, Inc., 2002