Analog Devices Inc. AD8278ARZ

Overview

AD8278ARZ 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 power-constrained 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 battery-powered voltage and current monitoring applications.

For engineers reviewing the AD8278ARZ datasheet, AD8278ARZ pinout, AD8278ARZ application, or AD8278ARZ equivalent, key selection criteria include its rail-to-rail input common-mode range beyond supplies (up to ±3×VS), laser-trimmed internal resistors for gain accuracy, rugged input overvoltage protection, and ultra-low 200 μA supply current per channel.

Technical Context

The AD8278ARZ integrates matched thin-film resistors and an op amp core optimized for differential-to-single-ended conversion with exceptional common-mode rejection. Its input stage supports common-mode voltages extending to −3(VS + 0.1) V and +3(VS − 1.5) V at G = ½, enabling direct measurement of high-side signals in industrial and automotive power rails.

It features enhanced slew rate (1.4 V/μs), low offset drift (±1 μV/°C max, Grade B), and gain drift (1 ppm/°C max), making it suitable for precision instrumentation amplifier building blocks where temperature stability and long-term accuracy are critical.

Key Specifications

Pinout & Package

AD8278ARZ is housed in an 8-lead SOIC package (SOIC_N, body width 3.9 mm, JEDEC MS-012). The package provides standard surface-mount compatibility and thermal resistance (θ_JA = 121°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD8276ARZ, AD8278ARZ offers lower power and integrated gain-setting resistors; compared with INA199A1DCKR, it provides wider common-mode range, true Kelvin sensing, and superior CMRR - making AD8278ARZ optimal for precision, low-power, high-voltage differential measurement.

Availability

AD8278ARZ is available at Aetrix Electronics and suitable for voltage measurement and monitoring, current measurement and monitoring, and portable, battery-powered equipment requiring stable component supply and guaranteed long-term availability.

Supply support for AD8278ARZ 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, communications, automotive, and healthcare markets.

The AD8278 belongs to Analog Devices' precision difference amplifier product line, engineered for low-power, high-accuracy signal conditioning in power-critical applications such as energy metering, motor control, and portable instrumentation.

FAQ

What is the maximum common-mode input voltage range for AD8278ARZ at G = ½?

The AD8278ARZ supports a common-mode input voltage range of −3(VS + 0.1) V to +3(VS − 1.5) V when configured for G = ½. For example, with ±15 V supplies, this extends from −45.3 V to +43.5 V - enabling direct high-side sensing in 48 V automotive or industrial systems without external level shifting. This specification is confirmed in Table 2 of the AD8278/AD8279 Rev. C datasheet.

Does AD8278ARZ require external resistors to set gain?

No, AD8278ARZ does not require external resistors to set gain. It integrates laser-trimmed thin-film resistors for factory-configured gains of G = ½ or G = 2. This eliminates resistor matching errors, board space, and thermal drift associated with discrete networks - ensuring consistent performance across units and temperature. The internal resistor network is explicitly shown in Figure 1 of the AD8278/AD8279 datasheet.

Can AD8278ARZ operate from a single 3.3 V supply?

Yes, AD8278ARZ operates from a single 3.3 V supply. Its specified single-supply range is 2.0 V to 36 V, and performance data in Table 4 confirms operation at +2.7 V with G = ½. At 3.3 V, it maintains 80 dB CMRR, 870 kHz bandwidth, and 200 μA supply current - making it suitable for low-voltage IoT sensor nodes and wearable electronics.

What is the purpose of the SENSE pin on AD8278ARZ?

The SENSE pin on AD8278ARZ enables true 4-wire (Kelvin) sensing by connecting directly to the load side of the sense resistor. This bypasses voltage drop in PCB traces or solder joints, eliminating measurement error caused by parasitic resistance. In high-accuracy current monitoring applications, using the SENSE pin improves gain accuracy by up to 0.1% versus 2-wire configurations - a feature documented in the "Circuit Information" section (page 16) of the datasheet.

Is AD8278ARZ RoHS compliant and qualified for industrial temperature range?

Yes, AD8278ARZ is fully RoHS compliant and specified for operation across the industrial temperature range of −40°C to +85°C. This qualification is stated in the "General Description" section (page 1) and confirmed in the "Specifications" tables (pages 3–6), where all parameters are guaranteed over this range. The device also meets JEDEC moisture sensitivity level (MSL) 1 requirements for standard reflow assembly.