Analog Devices Inc. AD8208WBRMZ

Overview

AD8208WBRMZ from Analog Devices is a high-voltage, precision difference amplifier optimized for high-side current sensing in automotive and industrial motor/solenoid control systems. It delivers 20 V/V system gain, ±2 mV initial input offset (referred to input), 80 dB minimum CMRR (dc to 10 kHz), −2 V to +45 V continuous common-mode input range, and operates from a single +5 V supply across −40°C to +125°C.

For engineers reviewing the AD8208WBRMZ datasheet, AD8208WBRMZ pinout, AD8208WBRMZ application, or AD8208WBRMZ equivalent, this device supports robust high-common-mode-voltage signal conditioning with integrated EMI filtering, buffered output, and configurable low-pass filtering-critical for accurate current monitoring in PWM-driven inductive loads.

Technical Context

The AD8208WBRMZ implements a two-stage architecture: a precision preamplifier (A1) with 10 V/V gain and 100 kΩ output resistance, followed by a unity-gain-buffered output stage (A2) with 2 V/V gain, yielding a total system gain of 20 V/V. Its laser-trimmed resistor network achieves <0.01% ratio matching, enabling ≥80 dB CMRR up to 10 kHz.

Input attenuation (1/14) and internal 350 mV bias allow operation with common-mode voltages as low as −2 V while maintaining A1 inputs within supply rails. The externally accessible A1 output (Pin 3) enables user-configurable gain adjustment and 1-pole or 2-pole low-pass filtering without external op-amps.

Key Specifications

Pinout & Package

AD8208WBRMZ is housed in an 8-lead MSOP package (RM-8), 3.0 mm × 3.0 mm × 0.85 mm, with exposed pad for thermal performance. Pin 7 (VS) accepts 4.5–5.5 V supply; Pin 2 (GND) is the analog ground reference; Pins 1 (−IN) and 8 (+IN) are high-impedance differential inputs; Pin 5 (OUT) delivers the buffered 20× amplified output.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA138UA/2K5 and MAX4080FASA+, the AD8208WBRMZ uniquely combines automotive qualification, −24 V to +80 V survival, EMI filtering, and user-accessible A1 output for integrated filtering-making it the only choice for robust, space-constrained high-side sensing in harsh automotive environments.

Availability

AD8208WBRMZ is available at Aetrix Electronics and suitable for automotive motor controls, solenoid diagnostics, and power management systems requiring stable component supply, long-term lifecycle assurance, and AEC-Q100-compliant performance.

Supply support for AD8208WBRMZ 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 automotive, industrial, communications, and healthcare markets since 1965.

The AD8208WBRMZ belongs to Analog Devices' precision current-sense amplifier product line, engineered specifically for accurate, noise-immune current measurement in high-dV/dt automotive power stages.

FAQ

What is the maximum common-mode voltage the AD8208WBRMZ can survive?

The AD8208WBRMZ is rated for continuous common-mode input voltages from −24 V to +80 V, exceeding automotive load-dump and jump-start requirements. This survival rating is distinct from its operating range (−2 V to +45 V), meaning the device remains undamaged and functional after transient exposure to these extremes-even if not actively measuring during the event. The AD8208WBRMZ maintains specification compliance only within its operating range, but its robust input structure prevents latch-up or permanent damage at survival limits.

Can the AD8208WBRMZ be used for low-side current sensing?

Yes, the AD8208WBRMZ supports low-side current sensing configurations, as confirmed in its Applications Information section (Figure 28). In this mode, the shunt is placed between the load and ground, with +IN connected to the load side and −IN to ground. The device's high CMRR (>80 dB) and input impedance (200 kΩ common-mode) reject ground noise and maintain linearity, making it suitable for systems where high-side placement is impractical-such as legacy designs or applications requiring ground-referenced signal chains.

How does the AD8208WBRMZ achieve its 80 dB CMRR up to 10 kHz?

The AD8208WBRMZ achieves ≥80 dB CMRR from dc to 10 kHz through laser trimming of its internal resistor network (RA, RB, RC, RF) to better than 0.01% ratio matching. This precision matching minimizes common-mode signal conversion to differential error at the preamplifier (A1) input. The 1/14 input attenuation further reduces common-mode swing before amplification, while the buffered A2 stage preserves rejection. Performance is validated per Table 1 and Figure 6, with CMRR maintained across temperature and supply variations.

What is the purpose of the A1 pin (Pin 3) on the AD8208WBRMZ?

Pin 3 (A1) provides direct access to the output of the AD8208WBRMZ's first-stage preamplifier, which has a fixed 10 V/V gain and 100 kΩ series resistance. This pin enables three key design flexibilities: (1) adding a capacitor to ground for 1-pole low-pass filtering, (2) connecting external resistors to adjust overall system gain above or below 20 V/V, and (3) implementing a 2-pole Sallen-Key filter using Pin 4 (A2 input). Its accessibility eliminates the need for external op-amps in most signal-conditioning paths.

Is the AD8208WBRMZ pin-compatible with other grades like AD8208WHRMZ?

No-the AD8208WBRMZ (WB grade, −40°C to +125°C) and AD8208WHRMZ (WH grade, −40°C to +150°C) share identical pinout, package outline, and electrical functionality, but they are not guaranteed pin-compatible replacements due to differences in quiescent current (2.7 mA vs. 3.0 mA typ), output voltage range limits, and thermal derating. While mechanical fit is identical, system-level validation-including thermal margin and output drive capability-is required before substitution, especially in +150°C ambient environments.