ADT7467 Datasheet, PDF (1/77 Pages) Analog Devices – dBCool Remote Thermal Monitor and Fan Controller

dBCool Remote Thermal
Monitor and Fan Controller
ADT7467
FEATURES
Controls and monitors up to 4 fans
High and low frequency fan drive signal
1 on-chip and 2 remote temperature sensors
Series resistance cancellation on the remote channel
Extended temperature measurement range, up to 191°C
Dynamic TMIN control mode intelligently optimizes
system acoustics
Automatic fan speed control mode manages 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, 3-wire, and 4-wire fan speed measurement
Limit comparison of all monitored values
Meets SMBus 2.0 electrical specifications
(fully SMBus 1.1 compliant)
GENERAL DESCRIPTION
The ADT7467 dBCool® controller is a thermal monitor and
multiple PWM fan controller for noise-sensitive or power-
sensitive applications requiring active system cooling. The
ADT7467 can drive a fan using either a low or high frequency
drive signal, monitor the temperature of up to two remote
sensor diodes plus its own internal temperature, and measure
and control the speed of up to four fans so that they operate at
the lowest possible speed for minimum acoustic noise.
The automatic fan speed control loop optimizes fan speed for a
given temperature. A unique dynamic TMIN 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 ADT7467 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
SCL SDA SMBALERT
PWM1
PWM2
PWM3
TACH1
TACH2
TACH3
TACH4
THERM
V_CC
D1+
D1–
D2+
D2–
V_CCP
PWM REGISTERS
AND
CONTROLLERS
HF & LF
V_CC TO ADT7467
SRC
BAND GAP
TEMP SENSOR
ACOUSTIC
ENHANCEMENT
CONTROL
FAN SPEED
COUNTER
PERFORMANCE
MONITORING
SERIAL BUS
INTERFACE
AUTOMATIC
FAN SPEED
CONTROL
ADDRESS
POINTER
REGISTER
DYNAMIC
T_MIN
CONTROL
PWM
CONFIGURATION
REGISTERS
INTERRUPT
MASKING
THERMAL
PROTECTION
ADT7467
INPUT
SIGNAL
CONDITIONING
AND
ANALOG
MULTIPLEXER
10-BIT
ADC
BAND GAP
REFERENCE
GND
INTERRUPT
STATUS
REGISTERS
LIMIT
COMPARATORS
VALUE AND
LIMIT
REGISTERS
Figure 1.
©2008 SCILLC. All rights reserved.
January 2008 – Rev. 3
Publication Order Number:
ADT7467/D