ADT7473 Remote Thermal Monitor and Fan Control The ADT7473/ADT74731 controller is a thermal monitor and multiple PWM fan controller for noise sensitive or power sensitive applications requiring active system cooling. The www.onsemi.com ADT7473/ADT74731 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 they operate at the lowest possible speed for minimum acoustic noise. The automatic fan speed control loop optimizes fan speed for a QSOP16 CASE 492 given temperature. A unique dynamic T control mode enables the MIN system thermals/acoustics to be intelligently managed. The PIN ASSIGNMENTS effectiveness of the systems thermal solution can be monitored using the THERM input. The ADT7473/ADT74731 also provide critical SCL 1 16 SDA thermal protection to the system using the bidirectional THERM pin GND 2 15 PWM1/XTO as an output to prevent system or component overheating. V 3 14 V CC CCP Features 4 13 TACH3 D1+ ADT7473 PWM2/ Controls and Monitors Up to 4 Fans 5 (Top View) 12 D1 SMBALERT High and Low Frequency Fan Drive Signal TACH1 6 11 D2+ TACH2 7 1 On-Chip and 2 Remote Temperature Sensors 10 D2 PWM3 8 9 TACH4/GPIO/ Series Resistance Cancellation on the Remote Channel THERM/ Extended Temperature Measurement Range, Up to 191C SMBALERT Dynamic T Control Mode Intelligently Optimizes System MIN SCL 1 16 SDA Acoustics GND 2 15 PWM1/XTO Automatic Fan Speed Control Mode Controls System Cooling Based V 3 14 V CC CCP on Measured Temperature TACH3/ 4 13 D1+ ADDR SELECT ADT74731 Enhanced Acoustic Mode Dramatically Reduces User Perception of PWM2/ 5 (Top View) 12 D1 Changing Fan Speeds THERM LATCH 6 11 TACH1 D2+ Thermal Protection Feature via THERM Output TACH2 7 10 D2 Monitors Performance Impact of Intel Pentium 4 Processor PWM3/ 8 9 TACH4/GPIO/ Thermal Control Circuit via THERM Input THERM/ ADDREN SMBALERT 3-wire and 4-wire Fan Speed Measurement Limit Comparison of All Monitored Values TOP MARKING BOTTOM MARKING Meets SMBus 2.0 Electrical Specifications (Fully SMBus 1.1 Compliant) ADT YYWW These Devices are Pb-Free, Halogen Free/BFR Free and are RoHS 74731 ZZZZ Compliant ARQZ ZZZZ ADT74731ARQZ = Specific Device Code = Pb-Free Package YYWW = Date Code ZZZZ = Assembly Lot Code ORDERING INFORMATION See detailed ordering and shipping information in the package dimensions section on page 72 of this data sheet. Semiconductor Components Industries, LLC, 2016 1 Publication Order Number: November, 2016 Rev. 11 ADT7473/DADT7473 *ADDREN *ADDR SELECT SCL SDA SMBALERT ADT7473/ADT74731 SMBus SERIAL BUS ADDRESS SELECTION INTERFACE PWM1 PWM REGISTERS ACOUSTIC AUTOMATIC AND ENHANCEMENT FAN SPEED PWM2 ADDRESS CONTROLLERS CONTROL CONTROL POINTER PWM3 (HF & LF) REGISTER DYNAMIC T PWM MIN TACH1 CONTROL CONFIGURATION REGISTERS TACH2 FAN SPEED COUNTER TACH3 TACH4 INTERRUPT MASKING PERFORMANCE MONITORING THERMAL *THERM LATCH INTERRUPT PROTECTION STATUS V to ADT7473/ADT74731 CC REGISTERS V CC D1+ LIMIT INPUT D1 10-BIT COMPARATORS SIGNAL SRC D2+ ADC CONDITIONING D2 AND ANALOG VALUE AND V CCP LIMIT MULTIPLEXER BAND GAP REGISTERS BAND GAP REFERENCE TEMP. SENSOR * PIN FUNCTION OLNY AVAILABLE ON THE ADT74731 GND Figure 1. Functional Block Diagram Table 1. ABSOLUTE MAXIMUM RATINGS Parameter Rating Unit Positive Supply Voltage (V ) 3.6 V CC Voltage on any Input or Output Pin 0.3 to +3.6 V Input Current at any Pin 5.0 mA Package Input Current 20 mA Maximum Junction Temperature (T ) 150 C J MAX Storage Temperature Range 65 to +150 C Lead Temperature, Soldering C IR Reflow Peak Temperature 260 Lead Temperature (Soldering, 10 sec) 300 ESD Rating 1,500 V Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality should not be assumed, damage may occur and reliability may be affected. NOTE: This device is ESD sensitive. Use standard ESD precautions when handling. www.onsemi.com 2