Analog Devices Inc. ADM1041ARQ

Overview

ADM1041ARQ from Analog Devices is a secondary-side power supply controller IC designed for N+1 redundant server power supplies, providing voltage regulation, current sharing, OrFET control, and comprehensive fault protection. It integrates a 2.5 V precision reference, SMBus/I²C interface, 352-byte field EEPROM, differential remote voltage sense (VS+/VS−), and differential current sense (CS+/CS−) with programmable gain up to 230 V/V.

For engineers reviewing the ADM1041ARQ datasheet, ADM1041ARQ pinout, ADM1041ARQ application, or ADM1041ARQ equivalent, this device supports digital calibration of load voltage (±0.1% trim step), current limit (±1.1%), soft-start period (0–40 ms), and reverse-voltage detection thresholds (20–250 mV) - critical for high-availability telecom and datacenter PSU designs requiring stable output, redundancy management, and fast fault response.

Technical Context

The ADM1041ARQ implements a closed-loop secondary-side control architecture where three key inputs - remote load voltage (VS+/VS−), load current (CS+/CS− or ICT), and current share bus (SHRO/SHRS) - are processed by dedicated analog amplifiers and error comparators to generate a PWM error signal (VCMP) for optocoupler-driven primary-side regulation. Its internal 2.5 V reference exhibits ±100 ppm/°C temperature stability and ±5 mV long-term drift over 1,000 hours at 125°C junction temperature.

It supports dual sensing modes: resistor-based current sense (gain selectable from 65× to 230×) or current transformer input (gain 2.57× or 4.5×), with independent DC offset and external divider tolerance trimming via 8-bit registers. The OrFET gate driver (FG pin) delivers open-drain N-channel output with <0.4 V low-level drop at 5 mA, enabling fast reverse-voltage shutdown (<2 µs response to load short).

Key Specifications

Pinout & Package

ADM1041ARQ is housed in a 24-lead QSOP package (5.3 mm × 7.6 mm, 0.65 mm pitch) with exposed pad for thermal dissipation. Pin functions are validated per Analog Devices Rev. A datasheet Figures 1, 14, and Pin Configuration table (Page 14).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar secondary-side power management applications.

Compared with ADM1041ARQ, LM5039MTX/NOPB shifts control to the primary side and removes digital configurability, while UCC39002DG4 provides only OrFET functionality - neither offers the integrated voltage/current/share/fault management stack that makes ADM1041ARQ suitable for N+1 server PSU compliance.

Availability

ADM1041ARQ is available at Aetrix Electronics and suitable for network servers, web servers, and redundant power supply control requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for ADM1041ARQ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving precision instrumentation, industrial automation, and communications markets since 1965.

The ADM1041ARQ belongs to Analog Devices' Power Management & Monitoring product line, engineered specifically for intelligent secondary-side control in high-availability AC/DC power supplies used in datacenters and telecom infrastructure.

FAQ

What is the primary function of the ADM1041ARQ in a power supply system?

The ADM1041ARQ serves as a secondary-side controller that manages output voltage regulation, current sharing across parallel modules, OrFET gate drive for redundancy protection, and comprehensive fault monitoring (OVP/UVP/OCP/OTP). It replaces multiple discrete supervisory and protection circuits in N+1 server PSUs, interfacing with the primary-side PWM via VCMP optocoupler feedback. Its design centers on minimizing external components while enabling digital calibration and real-time telemetry through SMBus.

Does the ADM1041ARQ support both resistor-based and current transformer-based current sensing?

Yes, the ADM1041ARQ supports two distinct current sensing methods: differential resistor-based sensing on CS+/CS− pins (with programmable gain from 65× to 230×) and current transformer input on ICT pin (with selectable gains of 2.57× or 4.5×). Selection is controlled via Reg 17h[7] and Reg 16h[2:0]. Each mode includes independent DC offset and external divider tolerance trimming, allowing flexible integration with various current measurement topologies without hardware redesign.

How does the ADM1041ARQ implement OrFET control, and what is its response time to a reverse-voltage fault?

The ADM1041ARQ drives an external N-channel MOSFET via its open-drain FG pin. When reverse voltage is detected across the sense resistor (FS/CS−), the internal comparator triggers FG low within 2 µs - faster than typical discrete solutions. This rapid shutdown prevents bus collapse during single-module failures such as rectifier shorts. The reverse-voltage threshold is digitally programmable from 20 mV to 250 mV in four steps (Reg 03h[7:6] and [5:4]), enabling precise tuning for different MOSFET R_DS(on) and layout parasitics.

What memory resources are available on the ADM1041ARQ for field configuration and calibration?

The ADM1041ARQ integrates two dedicated EEPROM blocks: a 160-byte calibration memory storing trimmed values for voltage, current, and timing parameters, and a 352-byte field data memory for runtime logging, fault history, or custom configuration storage. Both are accessible via SMBus using standard I²C protocols. Endurance is rated at 100 k write cycles, with data retention guaranteed for 100 years at 55°C junction temperature - supporting field updates and long-life deployment in unattended infrastructure.

Can the ADM1041ARQ operate without a microcontroller, and what standalone features does it provide?

Yes, the ADM1041ARQ supports fully autonomous operation without a host microcontroller. It performs voltage regulation, current sharing, OrFET control, and fault protection using internal analog loops and programmable thresholds stored in EEPROM. Standalone features include programmable soft-start (0–40 ms), load voltage margining (0.1% resolution), AC mains undervoltage detection (ac sense), and self-contained overvoltage/overcurrent/overtemperature protection - all configurable at power-up via EEPROM contents or hardwired pins like ADD0.