Analog Devices Inc. AD8418WBRZ

Overview

AD8418WBRZ from Analog Devices is a bidirectional, zero-drift current sense amplifier optimized for high-side and low-side shunt-based current measurement in automotive motor and solenoid control systems. It delivers 20 V/V gain, ±400 µV max input offset over −40°C to +125°C, −2 V to +70 V common-mode input range, 250 kHz bandwidth, and integrated EMI filters. Its ratiometric output offset adjustment supports precise bidirectional sensing in PWM-rich environments.

For engineers reviewing the AD8418WBRZ datasheet, AD8418WBRZ pinout, AD8418WBRZ application, or AD8418WBRZ equivalent, key selection criteria include guaranteed automotive qualification (AEC-Q100), survival up to −4 V to +85 V common-mode voltage, ±0.15% gain error over temperature, and SOIC_N package compatibility with legacy PCB layouts requiring robust high-voltage current monitoring.

Technical Context

The AD8418WBRZ employs a patented zero-drift architecture enabling <0.1 µV/°C typical offset drift while maintaining 250 kHz small-signal bandwidth-critical for accurate phase-current sampling in 3-phase motor drives. Its dual reference inputs (VREF1/VREF2) allow flexible output offset configuration including ratiometric mid-scale (VS/2) for bidirectional operation without external references.

EMI filtering is embedded at both inputs to suppress fast-rising PWM common-mode transients up to 1 V/ns, and its 86 dB CMRR (dc–10 kHz) ensures stable amplification across −2 V to +70 V operating common-mode range-even during inductive flyback events in solenoid control circuits.

Key Specifications

Pinout & Package

AD8418WBRZ is housed in an 8-lead SOIC_N (R-8) package per JEDEC MS-012-AA, with 1.27 mm lead pitch, 5.00 mm × 3.95 mm body, and gull-wing leads suitable for automated optical inspection and reflow soldering.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD8418WBRZ, AD8210ARZ trades offset stability and bidirectional flexibility for lower cost and simpler biasing, while INA240A1QDRQ1 prioritizes speed and extended common-mode survival at the expense of zero-drift performance and integrated offset control-making AD8418WBRZ optimal for thermally demanding, safety-critical automotive current sensing where accuracy and integration are paramount.

Availability

AD8418WBRZ is available at Aetrix Electronics and suitable for motor control, solenoid actuation, and diagnostic protection systems requiring stable component supply across automotive production lifecycles.

Supply support for AD8418WBRZ 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, and communications markets since 1965.

The AD8418 product line delivers precision current sensing for safety-critical automotive subsystems-designed specifically to meet AEC-Q100 requirements and replace discrete op-amp solutions in motor, solenoid, and battery management applications.

FAQ

What is the maximum common-mode voltage survival rating for AD8418WBRZ?

The AD8418WBRZ supports −4 V to +85 V common-mode voltage survival per Absolute Maximum Ratings. This enables robust operation during automotive load-dump transients and jump-start events without latch-up or permanent damage, while its continuous operating range remains −2 V to +70 V under normal conditions. The AD8418WBRZ maintains specified performance within this survival envelope when used with appropriate external protection circuitry.

Does AD8418WBRZ require external components for basic bidirectional current sensing?

No, AD8418WBRZ supports fully integrated bidirectional operation without external components: tying VREF1 to VS and VREF2 to GND configures a ratiometric mid-scale output at VS/2, enabling symmetric ±50 A measurement across a 10 mΩ shunt. This eliminates the need for precision external references or trimming resistors-reducing BOM count and layout area while maintaining accuracy over temperature and supply variation in the AD8418WBRZ.

How does AD8418WBRZ handle PWM-induced common-mode noise in motor control?

AD8418WBRZ incorporates patented EMI filtering and a zero-drift architecture that rejects fast common-mode transients up to 1 V/ns-common in MOSFET-switched H-bridges. Its 86 dB CMRR (dc–10 kHz) and input-stage hardening ensure stable 20 V/V gain even during rapid voltage slewing across the shunt, preventing erroneous current readings that could trigger false overcurrent faults in AD8418WBRZ-based motor controllers.

Is AD8418WBRZ pin-compatible with other members of the AD8418 family?

Yes, AD8418WBRZ shares identical 8-lead SOIC_N (R-8) pinout with AD8418BRZ and AD8418ARZ, enabling drop-in replacement across commercial, automotive, and industrial variants. All share identical pin functions (−IN, GND, VREF2, NC, OUT, VS, VREF1, +IN), allowing reuse of existing PCB layouts when upgrading to AEC-Q100-qualified AD8418WBRZ for automotive production.

What is the guaranteed gain error specification for AD8418WBRZ over temperature?

AD8418WBRZ guarantees ±0.15% gain error over the full −40°C to +125°C operating temperature range, as specified in the datasheet's "Gain Error Over Temperature" parameter. This tight tolerance-combined with ±8 ppm/°C gain vs. temperature drift-ensures minimal calibration burden in automotive ECUs where long-term accuracy across thermal cycling is required for AD8418WBRZ deployments.