Analog Devices Inc. ADM1041ARQ-2

Overview

ADM1041ARQ-2 from Analog Devices is a secondary-side controller IC for N+1 redundant server power supplies, providing voltage regulation, current sharing, OrFET control, and comprehensive fault protection. It features differential remote voltage sensing (VS+/VS−), programmable current sense gain (65–230 V/V), 2.5 V precision reference (±100 ppm/°C), SMBus/I²C interface, and integrated EEPROM for digital calibration. It operates at 5 V supply with −40°C to +85°C industrial temperature range.

For engineers reviewing the ADM1041ARQ-2 datasheet, ADM1041ARQ-2 pinout, ADM1041ARQ-2 application, or ADM1041ARQ-2 equivalent, this page delivers verified technical context, validated pin functions, real-world server PSU use cases, and two confirmed alternative controllers with documented functional and application differences.

Technical Context

The ADM1041ARQ-2 implements a closed-loop secondary-side control architecture that generates an optocoupler-compatible error signal (VCMP) by combining differential load voltage sense, current sense, and current share bus inputs. Its voltage error amplifier has 1 MHz GBW and ±250 µA output drive, while the current limit error amplifier provides 100–300 µA/V transconductance with programmable shutdown delay (1–4 s).

It supports dual current sensing modes-resistor-based (CS+/CS−) with 65–230× gain and transformer-based (ICT) with 2.57–4.5× gain-and integrates a dedicated OrFET gate driver (FG pin) with reverse-voltage detection (20–250 mV threshold, software-selectable). All trimming, timing, and protection thresholds are digitally configurable via its 352-byte SMBus-accessible EEPROM.

Key Specifications

Pinout & Package

ADM1041ARQ-2 is housed in a 24-lead QSOP package (5.3 mm × 7.6 mm, 0.635 mm pitch) with exposed pad for thermal performance. 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 UCD9222RGZR and LTC4357IMS8#PBF, the ADM1041ARQ-2 uniquely integrates voltage regulation, current sharing, OrFET control, AC/DC monitoring, and SMBus telemetry in a single IC - making it the only option qualified for fully autonomous N+1 server PSU housekeeping without external microcontrollers or support ICs.

Availability

ADM1041ARQ-2 is available at Aetrix Electronics and suitable for network servers, web server redundant PSUs, and telecom shelf power systems requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for ADM1041ARQ-2 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 industrial, automotive, communications, and computing markets.

The ADM1041ARQ-2 belongs to Analog Devices' Power Management IC product line, engineered specifically for intelligent secondary-side control in high-reliability, N+1 redundant AC/DC power supplies used in datacenter infrastructure.

FAQ

What is the primary function of the ADM1041ARQ-2 in a power supply design?

The ADM1041ARQ-2 serves as a standalone secondary-side controller that manages output voltage regulation, current sharing across redundant power supplies, OrFET gate drive for efficient ORing, and comprehensive fault protection-including overvoltage, undervoltage, overcurrent, overtemperature, and AC mains monitoring. It replaces manual calibration components and enables full digital configuration via SMBus, making it ideal for N+1 server PSUs. The ADM1041ARQ-2 integrates all these functions without requiring an external microcontroller.

Does the ADM1041ARQ-2 support both sense-resistor and current-transformer based current measurement?

Yes, the ADM1041ARQ-2 supports two distinct current sensing architectures: differential resistor-based sensing on CS+/CS− pins (with programmable gain from 65× to 230×) and transformer-based sensing on the ICT pin (with 2.57× or 4.5× gain). The selection is controlled by register bits (Reg 17h[7] and Reg 16h[2:0]), and each mode includes independent offset and gain calibration registers. This flexibility allows the ADM1041ARQ-2 to adapt to different power stage topologies and accuracy requirements in server and telecom PSUs.

How does the ADM1041ARQ-2 implement OrFET control, and what protection does it provide?

The ADM1041ARQ-2 implements OrFET control through its open-drain FG output pin, which drives the gate of an external N-channel MOSFET used to replace traditional ORing diodes. It continuously monitors reverse voltage across the MOSFET using the CS− (FS) pin and shuts down the FG output within 2 µs when reverse voltage exceeds a programmable threshold (20–250 mV). This prevents bus collapse during single-supply faults in N+1 configurations. The ADM1041ARQ-2 also reports OrFET status via the ORFETOK flag and SMBus registers.

Can the ADM1041ARQ-2 operate without a microcontroller, and what interfaces does it provide?

Yes, the ADM1041ARQ-2 is designed for standalone operation: it performs voltage regulation, current sharing, fault detection, and OrFET control autonomously using internal analog comparators, amplifiers, and EEPROM-stored calibration data. It also provides an SMBus/I²C interface (400 kHz compliant) for optional microcontroller integration-enabling real-time telemetry, remote configuration, and fault logging. Pins like AC_OK, DC_OK, and PSON support direct connection to system logic without protocol overhead. The ADM1041ARQ-2 thus supports both fully autonomous and host-managed power management architectures.

What package type and thermal characteristics does the ADM1041ARQ-2 use?

The ADM1041ARQ-2 is packaged in a 24-lead QSOP (Quarter-Size Outline Package) measuring 5.3 mm × 7.6 mm with 0.635 mm lead pitch and an exposed thermal pad. Its absolute maximum junction temperature is 150°C, and it is rated for continuous operation from −40°C to +85°C ambient. The datasheet specifies 450 mW maximum power dissipation at 25°C, and the exposed pad significantly improves thermal resistance to the PCB. This package enables high-density placement in server PSU modules while maintaining reliable thermal performance under full-load conditions. The ADM1041ARQ-2's thermal design is validated for use in convection-cooled and forced-air environments typical of 1U/2U server chassis.