ADT7490ARQZ

Thermal Management Overview

The ADT7490ARQZ is a remote thermal monitor and fan controller manufactured by onsemi, designed for noise-sensitive or power-sensitive applications requiring active system cooling. It features one local on-chip temperature sensor, two remote temperature sensors with series resistance cancellation, and a PECI interface for CPU thermal information. The device provides three PWM outputs to drive fans and four TACH inputs to measure fan speed. It operates within a supply voltage range of 3.0 V to 3.6 V and supports an operating temperature range from -40°C to +125°C. The component is housed in a 24-lead QSOP package.

Thermal Management Feature Summary

• Integrates local and remote temperature sensing capabilities with series resistance cancellation for accurate thermal monitoring.
• Supports automatic fan speed control using thermal data from PECI, remote, or local sensors to optimize acoustic noise.
• Includes a bidirectional THERM/SMBALERT pin for signaling out-of-limit and overtemperature conditions.
• Provides GPIO functionality for loadline setting, LED control, and other system-specific features.

Thermal Management Applications

• Personal Computers
• Servers

Thermal Management Procurement Notes

Verify the specific ordering suffix and package type against the manufacturer's current datasheet before procurement. Confirm that the component meets all required environmental and electrical specifications for the intended application. Check for any end-of-life notices or alternative part recommendations from onsemi. Ensure compatibility with existing system designs regarding pin assignments and register maps.

Thermal Management Selection Notes

Select this component for systems requiring precise thermal management and low-noise fan operation. Consider its compatibility with the ADT7473/ADT7475/ADT7476/ADT7476A family if footprint and register compatibility are needed. Evaluate the need for PECI interface support for CPU thermal information. Assess the requirement for multiple remote temperature sensors with series resistance cancellation.

Thermal Management Part Context

The ADT7490ARQZ belongs to the dBCool family of thermal monitors and fan controllers from onsemi. It is designed to provide comprehensive thermal management solutions for computing platforms. The device integrates multiple sensing and control functions into a single package, reducing board space and design complexity. Its compatibility with other devices in the family allows for flexible system configurations.

Thermal Management Replacement Considerations

The ADT7490 is footprint and register compatible with the ADT7473, ADT7475, ADT7476, and ADT7476A families. These parts can be considered as potential replacements if they meet the specific functional requirements of the application. Verify pinout and register map compatibility before substitution.

Thermal Management FAQ

What is the purpose of the PECI interface on the ADT7490?

The PECI interface allows the ADT7490 to monitor CPU thermal information and supports up to four PECI inputs on one pin. This enables the device to use CPU temperature data for automatic fan speed control.

How does the ADT7490 handle remote temperature sensor accuracy?

The ADT7490 includes series resistance cancellation (SRC) for its remote temperature sensors, which helps maintain accuracy even when there is resistance in the wiring connecting the sensors to the device.

Can the ADT7490 control both 3-wire and 4-wire fans?

Yes, the ADT7490 provides three high-frequency or low-frequency PWM outputs that can be used with either 3-wire or 4-wire fans. It also has four TACH inputs to measure the speed of these fans.