ADT7466 Datasheet, PDF (1/48 Pages) Analog Devices – dBCool Remote Thermal Controller and Voltage Monitor

dBCool^® Remote Thermal
Controller and Voltage Monitor
ADT7466
FEATURES
Monitors two analog voltages or thermistor temperature
inputs
One on-chip and up to two remote temperature sensors with
series resistance cancellation
Controls and monitors the speed of up to two fans
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 PROCHOT input
3-wire fan speed measurement
Limit comparison of all monitored values
SMBus 1.1 serial interface
GENERAL DESCRIPTION
The ADT7466 dBCool controller is a complete thermal monitor
and dual fan controller for noise-sensitive applications
requiring active system cooling. It can monitor two analog
voltages or the temperature of two thermistors, plus its own
supply voltage. 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 two 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. The effectiveness of the system’s
thermal solution can be monitored using the PROCHOT input
to time and monitor the PROCHOT output of the processor.
APPLICATIONS
Low acoustic noise notebook PCs
FUNCTIONAL BLOCK DIAGRAM
V_CC
SCL SDA ALERT
DRIVE1
DRIVE2
TACH1
TACH2
FANLOCK
FAN1_ON/
PROCHOT/
THERM
8-BIT
DAC
8-BIT
DAC
FAN1
ENABLE
D1+
D1–
AIN1/TH1/D2–
AIN2/TH2/D2+
SERIES
RESISTANCE
CANCELLATION
SERIES
RESISTANCE
CANCELLATION
BAND GAP
TEMPERATURE
SENSOR
V_FAN_MIN
V_FAN_ON
CONTROL
FAN
SPEED
MONITOR
ACOUSTIC
ENHANCEMENT
CONTROL
AUTOMATIC
FAN SPEED
CONTROL
PROCHOT
INPUT
SIGNAL
CONDITIONING
AND
ANALOG
MULTIPLEXER
10-BIT
ADC
BAND GAP
REFERENCE
GND
Figure 1.
Protected by U.S. Patent Numbers 6,188,189; 6,169,442; 6,097,239; 5,982,221; 5,867,012.
REFOUT
SERIAL BUS
INTERFACE
ADDRESS
POINTER
REGISTER
CONFIGURATION
REGISTERS
THERM
REGISTER
INTERRUPT
MASKING
INTERRUPT
STATUS
REGISTERS
LIMIT
COMPARATORS
VALUE AND
LIMIT
REGISTERS
ADT7466
©2010 SCILLC. All rights reserved.
May 2010 – Rev. 3
Publication Order Number:
ADT7466/D