AD8538ARZ - Precision Auto-Zero Op Amp | Analog Devices
MPN: AD8538ARZ ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.25 | $1.25 |
| 10 | $1.12 | $11.20 |
| 100 | $0.95 | $95.00 |
| 500 | $0.84 | $420.00 |
| 1,000 | $0.75 | $750.00 |
Drop-in alternatives for AD8538ARZ — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
AD8538ARZ-REEL7
✅ Drop-In📋 Reference alternative (not in catalog)
AD8539ARZ
✅ Drop-In✓ In Stock
$0.98 / Unit
View Datasheet →MCP6V11-E/SN
✅ Drop-In📋 Reference alternative (not in catalog)
OPA388IDR
✅ Drop-In📋 Reference alternative (not in catalog)
LMP7721MA
✅ Drop-In📋 Reference alternative (not in catalog)
AD8538ARZ Maximum Ratings & Electrical Characteristics
| Amplifier Type | Auto-Zero (Chopper) Op Amp |
| Number of Circuits | 1 |
| Supply Voltage - Single | 2.7 V to 5.5 V |
| Supply Voltage - Dual | ±1.35 V to ±2.75 V |
| Input Offset Voltage (max) | 13 µV |
| Input Offset Drift | 0.03 µV/°C |
| Input Bias Current (max) | 25 pA |
| Supply Current (max) | 215 µA at 5.0 V |
| Gain Bandwidth Product | [DATA_NEEDED: Gain Bandwidth Product] |
| Slew Rate | 0.4 V/µs |
| CMRR | [DATA_NEEDED: CMRR] |
| PSRR | [DATA_NEEDED: PSRR] |
| Operating Temperature Range | -40°C to +125°C |
| Package | 8-SOIC (SOIC-8) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
AD8538ARZ Pin Configuration
| Pin 1 | OUT — Amplifier output |
| Pin 2 | -IN — Inverting input |
| Pin 3 | +IN — Non-inverting input |
| Pin 4 | V- — Negative supply (or ground in single-supply operation) |
| Pin 5 | NC — No connect |
| Pin 6 | OUT — Amplifier output (duplicate for dual version, NC for single) |
| Pin 7 | V+ — Positive supply |
| Pin 8 | NC — No connect |
Safe Operating Area (SOA) & Thermal Characteristics
No official SOA curve available for this component. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.
Typical Applications
AD8538ARZ is suitable for 6 applications: Precision Current Sensing, Thermocouple Signal Conditioning, Medical Instrumentation, Battery-Powered Portable Devices, Sensor Interfaces, Industrial Process Control.
Precision Current Sensing
The AD8538ARZ's ultra-low offset voltage (13 µV max) and low input bias current (25 pA) enable accurate current measurement across shunt resistors. In a typical high-side current sense circuit, the op amp amplifies the small voltage drop across a shunt, and the auto-zero architecture ensures minimal offset error, which is critical for low-current measurements. The low supply current (215 µA) also makes it suitable for battery-powered monitors. For best accuracy, use a precision shunt resistor and keep the sense lines short to minimize noise pickup.
Recommended
Thermocouple Signal Conditioning
Thermocouples produce very small voltages (tens of microvolts per degree), requiring an amplifier with extremely low offset and drift. The AD8538ARZ's 13 µV max offset and 0.03 µV/°C drift ensure accurate temperature readings over a wide range. Its low input bias current (25 pA) minimizes errors from source impedance. The op amp can be configured as a differential amplifier with cold-junction compensation. The low power consumption is beneficial for portable temperature loggers. Use a low-pass filter at the output to reduce noise.
Recommended
Medical Instrumentation
In medical devices such as glucose monitors and ECG amplifiers, precision and low power are paramount. The AD8538ARZ provides the required accuracy with its auto-zero feature, eliminating offset errors that could affect diagnostic readings. Its low supply current extends battery life in portable devices. The small SOIC-8 package fits compact PCB layouts. The wide operating temperature range (-40°C to +125°C) ensures reliability in clinical environments. For safety, consider isolation barriers and proper ESD protection.
Recommended
Battery-Powered Portable Devices
The AD8538ARZ's low supply current (215 µA max) and low voltage operation (2.7 V to 5.5 V) make it ideal for battery-powered devices like handheld multimeters and portable sensors. Its precision ensures accurate measurements even as the battery voltage declines. The auto-zero feature maintains accuracy over time and temperature, reducing calibration needs. The SOIC-8 package is easy to assemble in high-volume production. To maximize battery life, use power-down modes if available and minimize the amplifier's duty cycle.
Recommended
Sensor Interfaces
The AD8538ARZ is well-suited for interfacing with various sensors, including RTDs, strain gauges, and pressure sensors. Its low offset and drift ensure accurate signal conditioning, while the low bias current prevents loading of high-impedance sensors. The amplifier can be used in bridge configurations to amplify small differential signals. The wide supply range allows operation from 3.3 V or 5 V systems. For best performance, use precision resistors in the bridge and shield the sensor lines from noise.
Recommended
Industrial Process Control
In industrial environments, the AD8538ARZ provides reliable precision for process control loops, such as 4-20 mA transmitters and PLC analog input modules. Its low offset and drift ensure accurate control over temperature variations. The wide operating temperature range (-40°C to +125°C) suits harsh conditions. The low power consumption reduces heat dissipation in control cabinets. The SOIC-8 package is robust and easy to integrate. For industrial applications, consider adding input protection against overvoltage and ESD.
Recommended
Recommended Products Summary
Engineering reference data for AD8538ARZ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AD8538ARZ-REEL7 | AD8539ARZ | MCP6V11-E/SN | OPA388IDR |
|---|---|---|---|---|---|
| Package | 8-SOIC | 8-SOIC | 8-SOIC | 8-SOIC | 8-SOIC |
| Brand | Analog Devices | Analog Devices | Analog Devices | Microchip Technology | Texas Instruments |
| Number of Channels | 1 | 1 | 2 | 1 | 1 |
| Input Offset Voltage (max) | 13 µV | 13 µV | 13 µV | 2 µV (typ) | 5 µV (max) |
| Input Bias Current (max) | 25 pA | 25 pA | 25 pA | 1 pA (typ) | 10 pA (typ) |
| Supply Current (max) | 215 µA | 215 µA | 430 µA (both amps) | 20 µA (typ) | 250 µA (typ) |
| Supply Voltage Range | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.0 V to 5.5 V | 2.5 V to 5.5 V |
| Slew Rate | 0.4 V/µs | 0.4 V/µs | 0.4 V/µs | 0.5 V/µs | 5 V/µs |
Key Differentiators
- Ultra-low offset voltage of 13 µV max (vs OPA388IDR)
- Very low input bias current of 25 pA (vs MCP6V11-E/SN)
- Low supply current of 215 µA max (vs OPA388IDR)
Design Notes
The AD8538ARZ operates from 2.7 V to 5.5 V single supply. Ensure the supply voltage is within this range and well-regulated. Use a 0.1 µF ceramic capacitor close to the V+ pin and a 10 µF bulk capacitor for low-frequency decoupling. For dual-supply operation, ensure both supplies are balanced and decoupled similarly.
For best performance, place the AD8538ARZ away from high-frequency digital circuits and switching regulators. Use a ground plane to minimize noise. Keep input traces short and shielded if necessary. The SOIC-8 package has a thermal pad? No, it does not, but ensure adequate copper area for heat dissipation if operating at high ambient temperatures.
Do not exceed the absolute maximum supply voltage of 6 V. The input common-mode range extends to the negative rail, but for best performance, keep inputs within the specified range. Avoid driving capacitive loads directly without a series resistor, as this can cause oscillation. Use proper ESD protection on inputs in harsh environments.
Compliance Information
RoHS compliance confirmed from distributor data. Other compliance information not explicitly stated in the provided data.
