AD8418WBRZ-RL - 20V/V Bidirectional Zero-Drift Current Sense Amp | ADI
MPN： AD8418WBRZ-RL ✗ 停產AD8418WBRZ-RL 概覽
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.
直接替換替代品，適用於 AD8418WBRZ-RL — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
AD8418WBRZ
✅ 直接替換📋 參考替代品（不在目錄中）
AD8418BRZ-RL
✅ 直接替換📋 參考替代品（不在目錄中）
AD8418BRZ
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
INA282BID
⚡ 相同封裝 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
AD8418WBRZ-RL 最大額定值與電氣特性
| Amplifier Type | Bidirectional zero-drift current sense amplifier |
| 通道數 | 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 |
| 供應電流 | 4.1 mA typical |
| Output Swing | Within 50 mV of rails |
| 工作溫度 | -40°C to +125°C |
| 封裝 | 8-lead SOIC |
| 安裝類型 | Surface Mount |
| Automotive Qualification | AEC-Q100 qualified |
| Packaging | Tape and Reel (-RL) |
| RoHS 狀態 | Compliant |
AD8418WBRZ-RL 8-lead soic 腳位配置指南
AD8418WBRZ-RL（8-lead soic 封裝）的腳位配置。 此類比元件具有輸入、輸出與電源腳位。偏移歸零、補償與致能腳位配置請參閱製造商資料表。適用於訊號調理與放大器電路。
無詳細腳位定義資料： AD8418WBRZ-RL.
請參閱 資料表 以查看完整腳位配置。
典型應用
AD8418WBRZ-RL 適用於 6 應用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.
推薦
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.
推薦
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.
推薦
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.
推薦
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.
推薦
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.
推薦
推薦產品摘要
工程參考資料，適用於 AD8418WBRZ-RL — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | 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 |
主要差異化特點
- Zero-drift accuracy with wide common-mode (對比INA282BID)
- Bidirectional sensing on a single supply (對比INA282BID)
- Package choice flexibility within family (對比AD8418WBRMZ-RL)
設計說明
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.
合規資訊
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.
