ADT7475_1110 Datasheet, PDF (1/58 Pages) ON Semiconductor – dbCOOL Remote Thermal Monitor and Fan Controller

ADT7475
dbCOOLt Remote Thermal
Monitor and Fan Controller
The ADT7475 dbCOOL controller is a thermal monitor and
multiple PWM fan controller for noise−sensitive or power−sensitive
applications requiring active system cooling. The ADT7475 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. The effectiveness of the system’s thermal solution
can be monitored using the THERM input. The ADT7475 also
provides critical thermal protection to the system using the
bidirectional THERM pin as an output to prevent system or
component overheating.
Features
• Controls and Monitors Up to 4 Fans
• High and Low Frequency Fan Drive Signal
• 1 On−Chip and 2 Remote Temperature Sensors
• Extended Temperature Measurement Range, Up to 191°C
• 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^R 4 Processor
• Thermal Control Circuit via THERM Input
• 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)
• These Devices are Pb−Free, Halogen Free/BFR Free and are RoHS
Compliant
http://onsemi.com
MARKING
DIAGRAM
QSOP−16
CASE 492
ADT7475
ARQZ
#YYWW
#
= Pb−Free Package
YYWW = Date Code
PIN ASSIGNMENT
SCL 1
GND 2
V_CC 3
TACH3 4
PWM2/ ₅
SMBALERT
TACH1 6
TACH2 7
PWM3 8
16 SDA
15 PWM1/XTO
ADT7475
TOP VIEW
14 V_CCP
13 D1+
12 D1–
11 D2+
10 D2–
9
TACH4/GPIO/THERM
SMBALERT
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 57 of this data sheet.
© Semiconductor Components Industries, LLC, 2011
1
October, 2011 − Rev. 5
Publication Order Number:
ADT7475/D