ADT7421ARZ-REEL

Overview

The ADT7421ARZ-REEL is a dual-channel digital thermometer and under/overtemperature alarm manufactured by onsemi. It features Beta Cancellation Technology for accurate measurement of small geometry CPU processes. The device includes an on-chip local sensor with 1°C resolution and a remote channel with 0.25°C resolution. It operates via a 2-Wire SMBus interface with a default address of 0x4C. Supply voltage ranges from 3.0 V to 3.6 V, with typical operating current of 3.0 mA at 4 conversions/sec. Local accuracy is ±2.75°C (0°C to +125°C), while remote accuracy varies between ±1.75°C and ±3.25°C depending on conditions. Measurement range is switchable between 0°C to +125°C and -40°C to +125°C.

Feature Summary

• Beta cancellation technology automatically compensates for beta variations in embedded thermal transistors of small geometry CPUs.
• Series resistance cancellation automatically removes up to 50 Ω of parasitic resistance from the remote temperature reading.
• Configurable ALERT output supports interrupt signaling or can be reconfigured as a second THERM comparator output.
• Extended switchable temperature measurement range allows selection between standard and wide operational limits.

Applications

• Desktop and notebook computers
• Industrial controllers
• Smart batteries
• Automotive systems
• Embedded systems

Procurement Notes

Verify the specific ordering suffix 'RZ' against the manufacturer's official documentation to confirm package type and tape/reel specifications. Confirm that the component meets RoHS compliance requirements for the intended assembly process. Check for any pin-compatible alternatives if supply constraints exist.

Selection Notes

Select this component when precise monitoring of small geometry processors is required due to its integrated beta cancellation feature. Ensure the system design accommodates the 3.0 V to 3.6 V supply range and utilizes pull-up resistors for the open-drain SMBus and alert outputs. Consider the extended temperature range configuration if operation below 0°C is necessary.

Part Context

The ADT7421 is part of onsemi's precision temperature sensor family designed for thermal management. It is pin- and register-compatible with the ADM1032, ADT7461, and ADT7461A. This compatibility facilitates direct upgrades or replacements in existing designs utilizing those legacy components without requiring schematic changes.

Replacement Considerations

Pin-compatible substitutes include the ADM1032, ADT7461, and ADT7461A. Verify register mapping consistency before replacement to ensure software compatibility.