AD8418WBRZ-RL - 20V/V Bidirectional Zero-Drift Current Sense Amp | ADI
部品番号: AD8418WBRZ-RL ✗ 生産終了| 数量 | 単価 | 小計 |
|---|---|---|
| 1 | $1.86 | $1.86 |
| 10 | $1.7 | $17.00 |
| 100 | $1.21 | $121.00 |
| 500 | $1.1 | $550.00 |
| 1,000 | $0.98 | $980.00 |
AD8418WBRZ-RL 概要
A current sense amplifier is a specialized instrumentation amplifier that amplifies the small voltage drop across a shunt resistor to measure load current precisely. It sits within the amplifier IC family, under analog signal conditioning ICs. The AD8418 belongs to the zero-drift amplifier class, which uses chopper stabilization to eliminate offset voltage and drift - a key requirement in closed-loop current control systems where long-term accuracy is essential.
Key features include a 250 kHz bandwidth, a supply current of only 4.1 mA typical, and an internally fixed gain that removes the need for external gain-setting resistors. The zero-drift architecture achieves a maximum offset of ±50 µV (10 µV typical) and a gain drift of ±1 ppm/°C across -40°C to +125°C, while the output stage swings within 50 mV of the rails to maximize dynamic range.
Technically, the AD8418 uses a chopper-stabilized input stage, and its reference pins allow output level shifting for bidirectional current measurement on a single supply. This flexibility supports both unidirectional and bidirectional sensing topologies without negative supplies.
Typical applications include automotive motor control, solenoid control, battery management, and power supply monitoring, where the wide common-mode range and AEC-Q100 qualification ensure reliable operation in harsh environments.
Design tip: drive the reference pins from a low-impedance source and use short shunt traces with proper supply decoupling to avoid gain errors and noise pickup.
ドロップイン代替品: AD8418WBRZ-RL — 同一パッケージでピン互換。PCBの作り直しが必要な異なるパッケージの部品は除外されています。
クイック比較ツール — 並列比較する代替部品を選択:
AD8418WBRZ
✅ ドロップイン📋 参考代替品（カタログ未掲載）
AD8418BRZ-RL
✅ ドロップイン📋 参考代替品（カタログ未掲載）
AD8418BRZ
✅ ドロップイン ⚠️ 仕様未検証📋 参考代替品（カタログ未掲載）
INA282BID
⚡ 同一パッケージ ⚠️ 仕様未検証📋 参考代替品（カタログ未掲載）
AD8418WBRZ-RL 最大定格＆電気的特性
| Amplifier Type | Bidirectional zero-drift current sense amplifier |
| チャネル数 | 1 |
| Gain | 20 V/V (fixed) |
| Gain Error | ±0.15% max over temperature |
| Common-Mode Voltage Range | -2 V to +70 V |
| Supply Voltage Range | 2.75 V to 5.5 V |
| Bandwidth | 250 kHz |
| Offset Voltage | ±50 µV max (10 µV typical) |
| Gain Drift | ±1 ppm/°C |
| 電源電流 | 4.1 mA typical |
| Output Swing | Within 50 mV of rails |
| 動作温度 | -40°C to +125°C |
| パッケージ | 8-lead SOIC |
| 実装タイプ | Surface Mount |
| Automotive Qualification | AEC-Q100 qualified |
| Packaging | Tape and Reel (-RL) |
| RoHS ステータス | Compliant |
AD8418WBRZ-RL 8-lead soic ピン配置ガイド
AD8418WBRZ-RL (8-lead soic パッケージ) のピン配置。 このアナログコンポーネントは、入力、出力、および電源ピンを備えています。オフセットナル、補償、イネーブルピンの設定については、メーカーのデータシートを参照してください。信号調整やアンプ回路に最適です。
詳細なピン配置データはありません: AD8418WBRZ-RL.
詳細は データシート をご参照ください。
主な用途
AD8418WBRZ-RL の用途: 6 件s: Automotive Motor Control Current Sensing, Battery Management Systems, Solenoid and Actuator Control, Power Supply and DC Bus Monitoring, 48V Mild-Hybrid Systems, Industrial Process Control.
Automotive Motor Control Current Sensing
The AD8418WBRZ-RL fits automotive motor control because its -2V to +70V common-mode range tolerates 12V/24V bus transients and its ±0.15% gain error preserves torque-control accuracy in closed-loop FOC schemes. Placed across a shunt in the DC bus or low-side return with a 250 kHz bandwidth, it resolves current ripples for control loops well beyond typical PWM sampling rates, while AEC-Q100 qualification and -40°C to +125°C operation ensure reliability under hood.
おすすめ
Battery Management Systems
For BMS pack current monitoring, the AD8418WBRZ-RL's zero-drift offset of ±50 µV max allows accurate measurement with small shunts, minimizing power loss, while ±1 ppm/°C gain drift keeps coulomb-counting accurate over battery life. Its -2V common-mode floor captures charging and regenerative reverse currents on a single supply, and the 20 V/V gain conveniently maps shunt drops into a 5V ADC range without extra gain stages.
おすすめ
Solenoid and Actuator Control
Solenoid drivers benefit from the AD8418WBRZ-RL's ability to sense current in high-side configurations up to +70V common-mode, enabling diagnostics of shorted loads and open circuits in 24V industrial and automotive actuators. The 250 kHz bandwidth captures peak-and-hold current waveforms, and the fixed 20 V/V gain simplifies design with no external gain resistors to drift, keeping trip thresholds accurate across temperature.
おすすめ
Power Supply and DC Bus Monitoring
In telecom and industrial power supplies, the AD8418WBRZ-RL monitors DC bus current with high-side shunts, where its wide common-mode range survives bus transients that would damage conventional amplifiers. The 10 µV typical offset enables millivolt-level shunt drops to be measured accurately, reducing shunt dissipation, and the output can be level-shifted via the REF pins to match any downstream ADC input range.
おすすめ
48V Mild-Hybrid Systems
The AD8418WBRZ-RL's +70V absolute common-mode capability provides headroom for 48V mild-hybrid battery rails and their transient overshoot. Its zero-drift architecture maintains ±0.15% gain accuracy over the full -40°C to +125°C range, supporting accurate load-current reporting to vehicle control units. AEC-Q100 qualification and tape-and-reel supply make it suitable for high-volume automotive production environments.
おすすめ
Industrial Process Control
In industrial current-loop and actuator monitoring, the AD8418WBRZ-RL provides a single-supply analog front end with bidirectional sensing via its REF pins, allowing positive and negative current indication around a mid-scale reference. The 4.1 mA supply current suits multichannel systems, and the chopper-stabilized input eliminates offset drift that would otherwise require periodic field calibration of current thresholds.
おすすめ
おすすめ製品の概要
エンジニアリング参考データ: AD8418WBRZ-RL — 比較、設計ガイダンス、コンプライアンス情報。
選定ガイド
代替品との比較
| パラメータ | この製品 | AD8418WBRZ | AD8418BRZ-RL | INA282BID |
|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Texas Instruments |
| Package | 8-SOIC | 8-SOIC - same | 8-SOIC - same | 8-SOIC |
| Gain | 20 V/V | 20 V/V | 20 V/V | 50 V/V |
| Common-Mode Range | -2 V to +70 V | -2 V to +70 V | -2 V to +70 V | -14 V to +80 V |
| AEC-Q100 | Qualified (W grade) | Qualified (W grade) | Qualified | Not qualified (standard) |
| Lifecycle | NRND | NRND | NRND | Active |
主な差別化要因
- Zero-drift accuracy with wide common-mode （vs INA282BID)
- Bidirectional sensing on a single supply （vs INA282BID)
- Package choice flexibility within family （vs AD8418WBRMZ-RL)
設計ノート
Use a Kelvin-connected shunt: route the amplifier input traces directly to the shunt resistor pads, not to shared current-carrying copper. With a ±50 µV maximum offset, even 1 mΩ of extra trace resistance adds error at high currents. Keep the input loop short and symmetrical, and place a 0.1 µF decoupling capacitor within 2 mm of the VS pin per Analog Devices layout guidance in the AD8418 datasheet typical application section.
Drive the REF pins from a low-impedance source. Because the reference-to-output gain is 1 V/V, any noise or impedance on REF appears directly at the output; a simple resistor divider without buffering introduces both gain error and offset shift. For bidirectional sensing, buffer the mid-scale reference with an op amp such as the AD8628 or use a precision reference IC.
The AD8418 is listed as NRND - Analog Devices does not recommend it for new designs, so plan a second-source strategy. Also note the WBRZ grade is specified for -40°C to +125°C; lower grades may not meet automotive requirements. Do not exceed the +70V common-mode rating during load-dump events without verifying transient conditions against the datasheet absolute maximum ratings.
コンプライアンス情報
RoHS compliance per distributor listings; AEC-Q100 qualification for the W automotive grade per ADI product data. REACH and halogen-free status not stated in provided data.
