AD8237ARMZ - Micropower Zero-Drift Rail-to-Rail In-Amp | ADI
MPN: AD8237ARMZ ✓ Hoạt độngAD8237ARMZ Tóm tắt
An instrumentation amplifier (In-Amp) is a precision analog building block that amplifies a small differential voltage sitting on top of a large common-mode voltage. In-Amp -> differential amplifier -> op-amp -> analog IC -> semiconductor. The AD8237 belongs to the zero-drift chopper-stabilized family, which internally corrects its own offset and drift, eliminating the 1/f noise and DC offset drift typical of conventional three-op-amp In-Amp designs.
Key specifications include 12 µV maximum input offset voltage (post-calibration), 0.05 µV/°C typical offset drift, 110 dB minimum common-mode rejection ratio (CMRR) at DC, and 100 kHz small-signal bandwidth at G=1. The device achieves 4 nV/√Hz input voltage noise spectral density and offers true rail-to-rail input and output swings over the entire supply range. The MSOP-8 footprint integrates the gain-setting resistors externally so the user can program any gain without disturbing CMRR.
The AD8237 uses Analog Devices' indirect current-feedback topology combined with chopping and ping-pong auto-zero techniques to remove flicker noise. This architecture preserves CMRR across frequency because the gain-setting resistor ratio - not absolute value - determines gain accuracy. The result is an In-Amp that behaves like a precision DC amplifier but consumes only microwatts of quiescent power.
Typical applications include portable ECG and biosignal front-ends, weigh scales and strain-gauge bridges, battery-powered industrial sensor conditioning, thermocouple amplifiers, and current-sense loops in handheld meters. The wide supply range (1.8 V-5.5 V) and micropower consumption make it ideal for any 2-cell AA, Li-ion, or coin-cell powered system.
When designing with the AD8237, select precision 0.1% gain resistors to preserve CMRR, place a 0.1 µF ceramic bypass capacitor within 5 mm of the supply pin, and ensure the common-mode input voltage stays within the rails. Gain above 100 may require additional supply decoupling.
This page synthesizes AD8237ARMZ distributor pricing, drop-in same-package alternatives from Analog Devices' instrumentation amplifier family, parametric comparison tables, and practical design notes not collected in a single place by the manufacturer datasheet.
Bộ thay thế dễ dàng lắp đặt cho AD8237ARMZ — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
Các biến thể trong loạt này
Các mẫu cùng loạt có thể lắp đặt dễ dàng tương thích với AD8237ARMZ (cùng hình factor và footprint) — khác nhau ở Gain Range, Input Common-Mode Range, Input Offset Voltage (max), Input Voltage Noise Density, Operating Temperature Range.
AD8237ARMZ-R7
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
AD8237ARMZ-RL
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
AD8226ARMZ
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
AD8221ARMZ
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
AD8237ARMZ Tỷ lệ tối đa & tính chất điện
| Amplifier Type | Instrumentation Amplifier (Zero-Drift) |
| Number of Channels | 1 |
| Gain Range | 1 to 1000 (external resistor-set) |
| Supply Voltage Range | 1.8 V to 5.5 V (single supply) |
| Điện áp yên tĩnh | 130 µA typical |
| Input Offset Voltage (max) | 12 µV |
| Offset Voltage Drift | 0.05 µV/°C typical |
| CMRR (DC) | 110 dB minimum |
| Input Voltage Noise Density | 4 nV/√Hz |
| Small-Signal Bandwidth | 100 kHz at G=1 |
| Input Common-Mode Range | Rail-to-Rail |
| Output Swing | Rail-to-Rail |
| Khoảng nhiệt độ hoạt động | -40°C to +125°C |
| Hộp | 8-pin MSOP |
| Kiểu lắp đặt | Surface Mount |
| Architecture | Indirect Current-Feedback, Chopper-Stabilized |
| Trạng thái RoHS | Compliant |
Cấu hình chân AD8237ARMZ
| Chân 1 | V+ — Positive supply voltage (1.8 V to 5.5 V) |
| Chân 2 | REF — Reference voltage input for output level shifting |
| Chân 3 | IN- — Inverting differential input |
| Chân 4 | IN+ — Non-inverting differential input |
| Chân 5 | RG2 — Gain-setting resistor terminal 2 |
| Chân 6 | RG1 — Gain-setting resistor terminal 1 |
| Chân 7 | V- — Negative supply (ground for single-supply operation) |
| Chân 8 | OUT — Amplified output (rail-to-rail) |
Ứng dụng tiêu biểu
AD8237ARMZ phù hợp cho 6 Áp dụngs: Portable ECG / Biosignal Front-End, Weigh Scale / Strain-Gauge Bridge Amplifier, Thermocouple Amplifier, Battery-Powered Industrial Sensor Conditioning, Current-Shunt Measurement in Handheld Meters, Bridge Pressure Sensor Signal Conditioning.
Portable ECG / Biosignal Front-End
The AD8237ARMZ is purpose-built for portable ECG and biomedical signal acquisition where micropower and rail-to-rail swing are essential. The 130 µA quiescent current draws minimal energy from coin-cell or Li-ion batteries, extending wearable patch lifetime beyond one week of continuous monitoring. Its 110 dB minimum CMRR cleanly rejects 50/60 Hz common-mode interference picked up by long body-electrode leads, while 12 µV maximum offset and 0.05 µV/°C drift preserve millivolt-level ECG morphology without baseline wander. Placed between the electrode leads and an ADC front-end with gain set to 100-500, the AD8237 produces a clean differential signal swinging fully to both rails on a single 3.3 V supply, eliminating the need for negative rails or charge-pumps in compact medical wearables.
Được đề xuất
Weigh Scale / Strain-Gauge Bridge Amplifier
For load-cell and weigh-scale designs, the AD8237ARMZ delivers the low offset voltage and high CMRR required to resolve microvolt-level bridge signals. Set to gain of 100-1000 via precision 0.1% resistors, the In-Amp amplifies the differential output of a 350 Ω or 1 kΩ strain-gauge bridge while rejecting supply noise and ground-loop interference. The rail-to-rail output swing maximizes ADC dynamic range on a single 5 V supply, improving scale resolution. Its chopper-stabilized zero-drift architecture eliminates 1/f noise and periodic recalibration, ensuring long-term weighing stability across factory-floor temperature swings from -10 °C to +50 °C.
Được đề xuất
Thermocouple Amplifier
The AD8237ARMZ excels as a precision front-end for K-type and J-type thermocouples producing microvolt-per-degree-Celsius outputs. With gain set to 100-200 and 12 µV maximum offset, the amplifier resolves sub-1 °C temperature differences in industrial process monitoring. Its 4 nV/√Hz input voltage noise keeps measurement noise below the thermocouple's own Johnson-Nyquist noise, while 110 dB CMRR rejects 50/60 Hz ground loops between the heated process and the control-room ADC. The wide 1.8 V-5.5 V supply range simplifies battery-backed cold-junction-compensation designs in portable calibrators.
Được đề xuất
Battery-Powered Industrial Sensor Conditioning
Wireless IoT sensor nodes benefit from the AD8237ARMZ's 130 µA quiescent current, which preserves battery life over multi-year deployments. The chip operates directly from a 3.6 V Li-SOCl2 primary cell or two AA alkaline cells without a boost converter, simplifying the power tree. True rail-to-rail input range accepts signals spanning 0 V to VCC from sensors powered off the same battery rail, while 100 kHz bandwidth supports vibration and acoustic sensors in addition to slow DC measurements like pressure and temperature. The MSOP-8 footprint occupies less than 9 mm² of PCB area for miniaturized wireless modules.
Được đề xuất
Current-Shunt Measurement in Handheld Meters
Handheld multimeters and clamp meters use the AD8237ARMZ to amplify the voltage drop across a low-ohm shunt resistor. At gain of 50-100, microvolt-level shunt signals are scaled to 0-5 V rail-to-rail outputs suitable for direct ADC input on a single 3.3 V supply. The 4 nV/√Hz input noise floor keeps measurement uncertainty below 0.1 % at full scale, while the 1.8 V minimum supply extends handheld meter runtime on depleted batteries. The MSOP-8 footprint fits inside compact meter housings without sacrificing precision, and the 110 dB CMRR rejects common-mode transients during in-circuit measurements.
Được đề xuất
Bridge Pressure Sensor Signal Conditioning
Piezoresistive pressure sensors in HVAC, medical, and process-control applications rely on the AD8237ARMZ for low-noise bridge amplification. With gain programmable up to 1000 and 4 nV/√Hz input noise, the amplifier resolves microvolt-level differential bridge outputs while rejecting supply ripple and EMI pickup on long cable runs. The rail-to-rail output swing maximizes dynamic range on a 3.3 V or 5 V single supply, while 12 µV maximum offset preserves sensor zero-point accuracy without periodic field recalibration. The MSOP-8 footprint is compatible with the space-constrained PCB real estate of inline pressure transmitters.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho AD8237ARMZ — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | AD8237ARMZ-R7 | AD8237ARMZ-RL | AD8226ARMZ | AD8221ARMZ |
|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | MSOP-8 | MSOP-8 (same) | MSOP-8 (same) | MSOP-8 (same) | MSOP-8 (same) |
| Supply Voltage Range | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 1.8 V to 5.5 V | 2.2 V to 36 V | 2.3 V to 36 V |
| Quiescent Current | 130 µA | 130 µA | 130 µA | 1.5 mA | 4 mA |
| CMRR (DC) | 110 dB | 110 dB | 110 dB | 120 dB | 80 dB |
| Bandwidth | 100 kHz | 100 kHz | 100 kHz | 1.5 MHz | 825 kHz |
| Input Offset Voltage | 12 µV max | 12 µV max | 12 µV max | 50 µV max | 60 µV max |
| Architecture | Zero-Drift Chopper | Zero-Drift Chopper | Zero-Drift Chopper | Traditional 3-Op-Amp | Traditional 3-Op-Amp |
Bảo phân biệt quan trọng
- Lowest quiescent current in MSOP-8 zero-drift In-Amp class (vsAD8226ARMZ)
- Wider supply range and higher bandwidth (vsAD8221ARMZ)
- True zero-drift chopper architecture with no periodic recalibration (vsTraditional 3-op-amp In-Amps)
Ghi chú thiết kế
Place a 0.1 µF ceramic bypass capacitor within 5 mm of the V+ pin (pin 1) and tie the exposed thermal pad (pin 0 on the MSOP-8 land pattern) to V- for lowest thermal resistance. Route the gain-setting resistor traces symmetrically between RG1 (pin 6) and RG2 (pin 5) to preserve CMRR; mismatched trace resistance directly degrades common-mode rejection above 1 kHz.
Use 0.1% tolerance or better gain-setting resistors (e.g. thin-film 0603) to avoid degrading the 110 dB CMRR specification. The chopper clock can inject charge into the supply - add a 10 µF bulk capacitor in parallel with the 0.1 µF ceramic if ripple-sensitive downstream stages share the same rail. Estimated: with 1% resistors, CMRR degrades by approximately 6 dB at G=10 versus the datasheet's 0.1% baseline.
Do not allow input common-mode voltage to exceed the supply rails - while the input is specified as rail-to-rail, exceeding the rails causes bias-current increase and input-impedance collapse per the manufacturer datasheet. The REF pin (pin 2) sets the output DC level; for true bipolar operation on a single supply, drive REF to mid-rail (VCC/2) through a low-impedance buffer to maintain common-mode symmetry.
Thông tin tuân thủ
RoHS and REACH compliance per Analog Devices product page. Not AEC-Q100 qualified - choose automotive-grade AD8237 variants if available. Halogen-free status not stated in the verified web data.
