AD8237ARMZ - Micropower Zero-Drift Rail-to-Rail In-Amp | ADI
MPN: AD8237ARMZ ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.12 | $3.12 |
| 10 | $2.78 | $27.80 |
| 100 | $2.31 | $231.00 |
| 500 | $1.89 | $945.00 |
| 1,000 | $1.45 | $1,450.00 |
AD8237ARMZ Overview
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.
Drop-in alternatives for AD8237ARMZ — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with AD8237ARMZ (same form factor and footprint) — differing in Gain Range, Input Common-Mode Range, Input Offset Voltage (max), Input Voltage Noise Density, Operating Temperature Range.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
AD8237ARMZ-R7
✅ Drop-In📋 Reference alternative (not in catalog)
AD8237ARMZ-RL
✅ Drop-In📋 Reference alternative (not in catalog)
AD8226ARMZ
✅ Drop-In📋 Reference alternative (not in catalog)
AD8221ARMZ
✅ Drop-In📋 Reference alternative (not in catalog)
AD8237ARMZ Maximum Ratings & Electrical Characteristics
| 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) |
| Quiescent Current | 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 |
| Operating Temperature Range | -40°C to +125°C |
| Package | 8-pin MSOP |
| Mounting Type | Surface Mount |
| Architecture | Indirect Current-Feedback, Chopper-Stabilized |
| RoHS Status | Compliant |
AD8237ARMZ Pin Configuration
| Pin 1 | V+ — Positive supply voltage (1.8 V to 5.5 V) |
| Pin 2 | REF — Reference voltage input for output level shifting |
| Pin 3 | IN- — Inverting differential input |
| Pin 4 | IN+ — Non-inverting differential input |
| Pin 5 | RG2 — Gain-setting resistor terminal 2 |
| Pin 6 | RG1 — Gain-setting resistor terminal 1 |
| Pin 7 | V- — Negative supply (ground for single-supply operation) |
| Pin 8 | OUT — Amplified output (rail-to-rail) |
Typical Applications
AD8237ARMZ is suitable for 6 applications: 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.
Recommended
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.
Recommended
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.
Recommended
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.
Recommended
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.
Recommended
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.
Recommended
Recommended Products Summary
Engineering reference data for AD8237ARMZ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | 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 |
Key Differentiators
- Lowest quiescent current in MSOP-8 zero-drift In-Amp class (vs AD8226ARMZ)
- Wider supply range and higher bandwidth (vs AD8221ARMZ)
- True zero-drift chopper architecture with no periodic recalibration (vs Traditional 3-op-amp In-Amps)
Design Notes
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.
Compliance Information
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.
