Analog Devices Inc. AD8278BRZ

Overview

AD8278BRZ from Analog Devices is a precision, low-power difference amplifier with fixed gain options of G = ½ or G = 2, designed for high-accuracy signal conditioning in space-constrained, battery-powered systems. It delivers 80 dB CMRR (dc to 20 kHz), 1 MHz bandwidth at G = ½, and operates from single supplies as low as 2.0 V up to 36 V - enabling use in industrial voltage monitoring and current sensing applications.

For engineers reviewing the AD8278BRZ datasheet, AD8278BRZ pinout, AD8278BRZ application, or AD8278BRZ equivalent, key selection criteria include its rail-to-rail input common-mode range beyond supplies (up to ±3×VS), 200 μA max supply current, laser-trimmed internal resistor network for <0.02% gain error, and rugged input overvoltage protection up to ±40 V beyond rails.

Technical Context

The AD8278BRZ integrates matched thin-film resistors and a precision op amp in an 8-lead SOIC package, forming a fully differential input stage with SENSE and REF terminals enabling Kelvin-sensing configurations. Its architecture supports both difference amplification (G = ½ or 2) and precision single-ended gain configurations (e.g., +½, −2, +3) without external components.

It features enhanced slew rate (1.4 V/μs), low offset drift (±1 μV/°C max), and wide supply flexibility: single-supply (2.0 V to 36 V) or dual-supply (±2 V to ±18 V). Input common-mode range extends to −3(VS + 0.1) V to +3(VS − 1.5) V at G = ½, making it suitable for high-side current sensing in automotive and industrial power rails.

Key Specifications

Pinout & Package

AD8278BRZ is housed in an 8-lead SOIC package (JEDEC MS-012AA, 150 mil width), with thermal resistance θJA = 121°C/W on a 4-layer board. Pin 8 is NC (no connect); all other pins are electrically active and functionally defined per Analog Devices Rev. C datasheet.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar difference amplifier applications.

Compared with AD8276ARZ and INA199A2DRVT, the AD8278BRZ uniquely combines programmable gain (½ or 2), ultra-low power (200 μA), and rail-exceeding input range - making it the only option among the three suitable for wide-supply, low-power, high-CMRR general-purpose difference amplification.

Availability

AD8278BRZ is available at Aetrix Electronics and suitable for industrial voltage monitoring, high-side current sensing, and portable battery management systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for AD8278BRZ 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, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA.

The AD8278 is part of Analog Devices' precision signal conditioning portfolio, engineered for low-power, high-accuracy applications including industrial automation, test equipment, and portable instrumentation where size, power, and performance are tightly constrained.

FAQ

What gain options does the AD8278BRZ support, and how are they selected?

The AD8278BRZ supports two fixed gain configurations: G = ½ and G = 2. These are implemented via internal laser-trimmed resistor networks and require no external components or configuration pins. Gain is determined during manufacturing and is immutable per device variant - the AD8278BRZ is specifically the G = ½ version. To use G = 2, the AD8278ARMZ (MSOP) or AD8278BRMZ (SOIC) variants must be selected per the Analog Devices ordering guide.

Can the AD8278BRZ operate from a single 3.3 V supply, and what is its output swing under that condition?

Yes, the AD8278BRZ operates from a single 3.3 V supply (within its 2.0 V to 36 V range). At TA = 25°C and RL = 10 kΩ, its output swing is specified as −VS + 0.1 V to +VS − 0.15 V - i.e., approximately 0.1 V to 3.15 V. This rail-to-rail capability enables direct interfacing with 3.3 V ADCs without level-shifting circuitry, preserving dynamic range and simplifying design.

Does the AD8278BRZ require external resistors for gain setting or filtering?

No, the AD8278BRZ requires no external resistors for gain setting - its G = ½ ratio is achieved via on-chip, laser-trimmed 40 kΩ/20 kΩ resistor networks. External resistors are optional only for noise filtering (e.g., RC networks on +IN/−IN) or output load isolation. The integrated design eliminates matching errors and temperature drift associated with discrete resistor solutions, directly improving system accuracy and reliability.

How does the SENSE pin (Pin 5) improve measurement accuracy in the AD8278BRZ?

The SENSE pin (Pin 5) provides a Kelvin sense path for the output node, allowing the AD8278BRZ to regulate its output voltage based on the actual load point rather than the amplifier's output pad. This compensates for voltage drop across PCB traces or connectors, maintaining gain accuracy even under high-current or long-trace conditions - critical in precision current sensing and power supply feedback applications where trace resistance could introduce >0.5% error.

Is the AD8278BRZ RoHS compliant and qualified for industrial temperature operation?

Yes, the AD8278BRZ is fully RoHS compliant and specified for operation across the industrial temperature range of −40°C to +85°C. Its guaranteed performance parameters - including 200 μA max supply current, 80 dB CMRR, and ±1 μV/°C offset drift - are validated over this full range per Analog Devices Rev. C datasheet, making it suitable for deployment in factory automation, energy infrastructure, and outdoor embedded systems.