Analog Devices Inc. 5B31-05-MB

Overview

5B31-05-MB from Analog Devices is a single-channel isolated voltage input signal conditioner that accepts ±5 V analog inputs and delivers 0 V to +5 V output with ±0.05% span accuracy, 1500 V_rms continuous isolation, and 4 Hz low-pass filtering-used in industrial programmable controllers and microcomputer-based measurement systems for noise-immune analog signal conditioning.

For engineers reviewing the 5B31-05-MB datasheet, 5B31-05-MB pinout, 5B31-05-MB application, or 5B31-05-MB equivalent, key selection considerations include its field-side floating differential input, chopper-stabilized amplifier (±20 µV/°C input offset drift), active-low output enable control, 240 V_rms input terminal withstand rating, and FM/CSA Class 1 Division 2 hazardous location certification.

Technical Context

The 5B31-05-MB employs transformer-coupled isolation with proprietary modulation for linear signal transfer and integrates a chopper-stabilized input amplifier delivering ±20 µV/°C input offset drift and ±50 ppm/°C gain drift. Its differential field-side input is fully floating, eliminating ground loop dependencies.

Internal multi-pole filtering provides 4 Hz –3 dB bandwidth, achieving 160 dB common-mode rejection at 50/60 Hz with 1 kΩ source imbalance and 60 dB normal-mode rejection. The output stage includes a series switch controlled by an active-low enable input and buffers to 50 Ω output impedance.

Key Specifications

Pinout & Package

Package: 2.275" × 2.375" × 0.595" (57.8 mm × 59.1 mm × 15.1 mm) potted module with standardized 5B Series footprint and screw-terminal field connections.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar isolated voltage input conditioning applications.

Compared with 5B31-05-MB, the 5B31-05 omits mechanical mounting features but retains identical signal conditioning performance, while ADUM3160BRWZ serves a fundamentally different digital isolation purpose and cannot substitute for analog voltage input conditioning.

Availability

5B31-05-MB is available at Aetrix Electronics and suitable for industrial programmable controllers, microcomputer-based measurement systems, and analog recorder interfaces requiring stable component supply, long-term lifecycle support, and certified hazardous-location compliance.

Supply support for 5B31-05-MB 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 semiconductor company specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision measurement and industrial control.

The 5B Series - including 5B31-05-MB - was designed specifically for rugged industrial signal conditioning, combining transformer isolation, chopper stabilization, and FM/CSA-certified safety in a hot-swappable modular format.

FAQ

What is the input impedance of the 5B31-05-MB when powered on?

The 5B31-05-MB has a powered-on input resistance of 650 kΩ, measured across pins 2 (LOW –) and 3 (HIGH +). This value remains stable across the full ±5 V input range and supports direct connection to medium-impedance voltage sources without loading error. The 5B31-05-MB maintains this impedance regardless of output enable state or temperature within its rated operating range.

Does the 5B31-05-MB require external power supply decoupling?

The 5B31-05-MB operates from a +5 V ±5% supply and draws 30 mA. While the module includes internal regulation and filtering, Analog Devices recommends using a 10 µF tantalum capacitor and 0.1 µF ceramic capacitor in parallel at the power input per the 5B Series User Manual. This ensures stable operation under transient load conditions and meets EN50082-1 immunity requirements for the 5B31-05-MB.

Can the 5B31-05-MB output drive a 10 kΩ load without accuracy degradation?

Yes - the 5B31-05-MB specifies performance for loads heavier than 50 kΩ, and its 0–5 V output maintains ±0.05% span accuracy with RL > 50 kΩ. Driving a 10 kΩ load introduces measurable nonlinearity and gain drift; therefore, the 5B31-05-MB should be used with ≥50 kΩ loads or buffered via an op-amp follower if lower impedances are required.

What does the "MB" suffix indicate in 5B31-05-MB?

The "MB" suffix denotes a mechanical variant of the 5B31-05 module that includes a factory-installed mounting bracket compatible with standard 5B Series backplanes. This bracket enables secure hot-swap insertion and retention in industrial rack-mount systems. The 5B31-05-MB shares identical electrical specifications, isolation ratings, and signal conditioning performance with the base 5B31-05 model.

Is the 5B31-05-MB compatible with 5B01 and 5B08 backplanes?

Yes - the 5B31-05-MB is fully mix-and-match and hot-swappable with all 5B Series backplanes, including the 5B01 and 5B08. Its pinout, dimensions, and power requirements match the family standard. The enable input is internally pulled low on these backplanes, ensuring the output switch remains active unless overridden - confirming seamless interoperability of the 5B31-05-MB in existing 5B infrastructure.