©
Semiconductor Components Industries, LLC, 2016
February, 2016 − Rev. 7
1
Publication Order Number:
ADT7476A/D
ADT7476A
Remote Thermal Controller
and Voltage Monitor
The ADT7476A controller is a thermal monitor and multiple PWM
fan controller for noise-sensitive or power-sensitive applications
requiring active system cooling. The ADT7476A can drive a fan using
either a low or high frequency drive signal and can monitor the
temperature of up to two remote sensor diodes plus its own internal
temperature. The part also measures and controls the speed of up to
four fans, so the fans 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 ADT7476A
also provides critical thermal protection to the system using the
bidirectional THERM pin as an output to prevent system or
component overheating.
Features
•
Monitors Up to Five Voltages
•
Improved TACH and PWM Performance
•
Controls and Monitors Up to Four Fans
•
High and Low Frequency Fan Drive Signal
•
One On-Chip and Two 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
®
4 Processor
•
Thermal Control Circuit via THERM Input
•
3-wire and 4-wire Fan Speed Measurement
•
Limit Comparison of All Monitored Values
•
5.0 V Support on all TACH and PWM Channels
•
Meets SMBus 2.0 Electrical Specifications
•
This Device is Pb-Free, Halogen Free and is RoHS Compliant
www.onsemi.com
PIN ASSIGNMENT
See detailed ordering and shipping information in the package
dimensions section on page 68 of this data sheet.
ORDERING INFORMATION
MARKING DIAGRAMS
QSOP−24 NB
CASE 492B
+2.5V
IN
/THERM
PWM1/XTO
V
CCP
+12V
IN
/VID5
+5V
IN
D1+
*TACH4/THERM/SMBALERT/GPIO6/ADDR SELECT
VID4/GPIO4
SDA
SCL
GND
V
CC
VID0/GPIO0
VID1/GPIO1
VID2/GPIO2
PWM2/
SMBALERT
24
23
22
21
20
19
18
17
8
7
6
5
4
3
2
1
ADT7476A
16
9
15
10
14
11
13
12
VID3/GPIO3
TACH3
TACH1
TACH2
D1−
D2+
D2−
PWM3/ADDREN
*
(Top View)
ADT7476AARQZ = Specific Device Code
#
= Pb-Free Package
YYWW
= Date Code
xxxx
= Assembly Lot Code
ADT7476AARQZ
#YYWW
xxxx
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