ADM1025AARQ-REEL

Overview

The ADM1025AARQ-REEL is a low-cost PC hardware monitor ASIC manufactured by Analog Devices Inc. It provides measurement and limit comparison of system parameters via an I²C-compatible System Management Bus (SMBus). The device features up to eight measurement channels, including five voltage inputs for monitoring 2.5 V, 3.3 V, 5 V, and 12 V supplies, plus internal VCC monitoring. It supports remote temperature sensing with a diode-connected transistor and includes an on-chip band gap sensor. Key specifications include a supply voltage range of 3.0 V to 5.5 V, typical standby current of 500 µA, and open-drain VID inputs.

Feature Summary

• Supports sequential measurement of multiple analog voltage inputs and temperature sensors with programmable limit comparisons.
• Features an I²C-compatible SMBus interface for serial data communication and device configuration.
• Includes dedicated digital inputs for reading processor core voltage ID bits (VID) from the motherboard.

Applications

• Network servers and personal computers
• Microprocessor-based office equipment
• Test equipment and measuring instruments

Procurement Notes

Verify that the specific ordering suffix ARQ corresponds to the open-drain VID input variant rather than the integrated pull-up version. Confirm the REEL7 packaging designation matches the required tape-and-reel quantity for production integration. Ensure the component meets the specified operating temperature range for the target application environment.

Selection Notes

Select the ADM1025A variant specifically when open-drain VID inputs are required for the system design. The standard ADM1025 model includes integrated 100 kΩ pull-ups on the VID pins, which may conflict with external circuitry. Verify that the SMBus address configuration via the ADD pin aligns with other devices on the bus to prevent communication conflicts.

Part Context

This component belongs to the ADM1025 family of hardware monitor ASICs designed for microprocessor-based systems. It serves as a comprehensive solution for monitoring power rails and thermal conditions in computing environments. The device integrates analog-to-digital conversion and limit comparators to provide real-time status feedback via a serial interface.

Replacement Considerations

The ADM1025ARQ is the primary alternative within the same package, differing only by the inclusion of integrated 100 kΩ pull-up resistors on the VID pins instead of open-drain outputs. No other direct cross-model replacements are documented in the provided source material.