ADT7490 Remote Thermal Monitor and Fan Controller with PECI Interface The ADT7490 is a thermal monitor and multiple PWM fan controller for noise-sensitive or power-sensitive applications requiring www.onsemi.com active system cooling. The ADT7490 includes a local temperature sensor, two remote temperature sensors including series resistance cancellation, and monitors CPU temperature with a PECI interface. The ADT7490 can drive a fan using either a low or high frequency drive signal, and measure and control the speed of up to four fans so they operate at the lowest possible speed for minimum acoustic noise. QSOP24 NB The automatic fan speed control loop optimizes fan speed CASE 492B for a given temperature using the PECI, remote, or local temperature information. The effectiveness of the systems thermal solution can be PIN ASSIGNMENT monitored using the THERM input. The ADT7490 also provides critical thermal protection to the system using the bidirectional SDA 1 24 PWM1/XTO THERM/SMBALERT pin as an output to prevent system or SCL 2 23 V CCP component overheating. GND 3 +2.5V /THERM 22 IN Features 4 21 V +12V CC IN Temperature Measurement GPIO1 5 20 +5V IN 1 Local On-Chip Temperature Sensor GPIO2 6 19 I MON ADT7490 2 Remote Temperature Sensors PECI 7 18 D1+ 3 Current External Temperature Sensors with Series Resistance V 8 17 D1 TT Cancellation (SRC) TACH3 9 16 D2+ PECI Interface for CPU Thermal Information and Support of Up PWM2/ 10 15 D2 to 4 PECI Inputs on 1 Pin SMBALERT 11 14 TACH1 * Fan Drive and Fan Speed Control 12 TACH2 13 PWM3/ADDREN 3 High Frequency or Low Frequency PWM Outputs for Use with 3-wire or 4-wire Fans *TACH4/THERM/SMBALERT/ADDR SELECT 4 TACH Inputs to Measure Fan Speed OS Independent Automatic Fan Speed Control Based on Thermal Information MARKING DIAGRAMS Dynamic T Control Mode to Optimize System Acoustics MIN Default Startup at 100% PWM for All Fans for Robust Operation 1 Bidirectional THERM/SMBALERT Pin to Flag Out-of-Limit and ADT7490 ARQZ Assembly Lot Overtemperature Conditions DateCode GPIO Functionality to Support Extra Features Can be Used for Loadline Setting for Voltage Regulation, LED Control, or Other Functions TOP MARKING BOTTOM MARKING I Monitoring for CPU Current and Power Information MON = Pb-Free Package Footprint and Register Compatible with ADT7473/ADT7475/ ADT7476/ADT7476A Family of Fan Controllers ORDERING INFORMATION SMBus Interface with Addressing Capability for Up to 3 Devices See detailed ordering and shipping information on page 74 of this data sheet. Applications Personal Computers Servers Semiconductor Components Industries, LLC, 2016 1 Publication Order Number: January, 2016 Rev. 6 ADT7490/DADT7490 ADDR SELECT SCL SDA ADT7490 SMBus SERIAL BUS ADDRESS INTERFACE SELECTION GPIO1 GPIO ADDRESS REGISTER GPIO2 POINTER REGISTER PERFORMANCE THERM/ SMBALERT MONITORING PWM CONFIGURATION THERMAL REGISTERS PROTECTION TACH1 INTERRUPT TACH2 MASKING FAN SPEED COUNTER TACH3 TACH4 AUTOMATIC FAN SPEED PWM1 PWM REGISTERS CONTROL ACOUSTIC PWM2 AND CONTROLLERS ENHANCEMENT (HF AND LF) PWM3 DYNAMIC T MIN CONTROL PECI INTERRUPT PECI INTERFACE STATUS REGISTERS ACOUSTIC V TT ENHANCEMENT V CC CONTROL LIMIT V CCP COMPARATORS +12V IN 10-BIT +5V IN INPUT ADC +2.5V SIGNAL IN VALUE AND CONDITIONING I LIMIT MON AND REGISTERS D1+ ANALOG BAND GAP MULTIPLEXER D1 REFERENCE D2+ D2 BAND GAP TEMP. SENSOR GND Figure 1. Functional Block Diagram www.onsemi.com 2