ADM1281-1AACPZ-RL

Overview

The ADM1281-1AACPZ-RL is a low-voltage hot swap controller manufactured by Analog Devices Inc. It operates within a supply voltage range of 4.5 V to 20 V and features a single channel. The device utilizes a 32-lead LFCSP package with dimensions of 5 mm x 5 mm. It includes an integrated 12-bit ADC for monitoring current, power, voltage, and temperature via a PMBus interface. The operating temperature range spans from -40 °C to +85 °C, with a typical quiescent current of 5.5 mA.

Feature Summary

• Integrated 12-bit ADC provides high-resolution back-read capabilities for load current, input/output voltage, and die temperature through the PMBus interface.
• Supports constant power foldback to enforce stricter Field-Effect Transistor Safe Operating Area (SOA) protection during fault conditions.
• Features programmable current limiting thresholds ranging from 5 mV to 25 mV via external resistors, allowing precise control over load ramp-up.
• Includes remote temperature detection with configurable warning and shutdown thresholds to monitor thermal health of the system.

Applications

• Server blade insertion and removal
• Telecommunications and data communication equipment
• Power monitoring and budgeting systems

Procurement Notes

Verify the specific suffix '1AA' against the official datasheet to confirm pinout and feature configuration differences compared to other variants in the ADM1281 family. Ensure compatibility with the intended PMBus implementation and check for any recent Product Change Notifications regarding manufacturing updates or obsolescence status before finalizing procurement plans.

Selection Notes

Select this component when precise digital monitoring of power parameters is required alongside hot swap protection. The integrated ADC eliminates the need for external sensing circuits, reducing bill of materials complexity. Consider the 32-lead LFCSP package for space-constrained designs requiring robust thermal performance and high-density mounting on the printed circuit board.

Part Context

This part belongs to the ADM1281 series of hot swap controllers designed for low-voltage applications. It serves as an advanced solution for protecting circuits during insertion into live backplanes. The series emphasizes digital control and monitoring capabilities, distinguishing it from older analog-only controllers by offering detailed telemetry and programmable protection thresholds.

Replacement Considerations

The ADM1278 is documented as a predecessor in the product line. Verify if the ADM1278-1ACPZ-RL is available as a direct substitute, noting that the ADM1278 may lack the integrated 12-bit ADC and advanced digital monitoring features present in the ADM1281 series.

FAQ

How is the current limit adjusted on the ADM1281?

The current limit is set using an external resistor connected to the VSENSE pins, allowing for programmable thresholds between 5 mV and 25 mV.

What interface is used for accessing the internal ADC data?

The device uses a PMBus interface to provide access to the 12-bit ADC data for current, voltage, power, and temperature readings.