Part A
AD8221ARZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 4567 PCS
- Package
- SOIC-8
- Series
- Linear - Amplificadores - Instrumentação, OP Amps, Buffer Amps
Replacement verdict
Compatible functional replacement candidate
The AD8221ARZ and AD8221AR are functionally equivalent instrumentation amplifiers from the same manufacturer, sharing identical electrical specifications, package type, and temperature range. The AD8221ARZ is the RoHS-compliant, lead-free version of the AD8221AR, making it a suitable drop-in replacement in most applications where environmental compliance is required.
Package Type
High match
Gain Range
High match
Operating Temperature Range
High match
RoHS Compliance
Validation required
Parts at a glance
Part B
AD8221AR
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 5847 PCS
- Series
- Linear - Amplifiers - Instrumentation, Op Amps, Buffer Amps
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD8221ARZ | AD8221AR | Why it matters |
|---|---|---|---|
| Amplifier Type | Instrumentation Amplifier | Instrumentation Amplifier | Both parts are the same functional amplifier type, so they serve the same signal-conditioning role. |
| Number of Channels | 1 | 1 | Channel count must match for direct circuit substitution. |
| Gain Bandwidth Product | 825 kHz | 825 kHz | Determines the achievable closed-loop bandwidth at a given gain; identical values mean equivalent AC performance. |
| Input Offset Voltage (max) | 60 µV | 60 µV | Offset voltage directly affects DC accuracy; matching values ensure equivalent precision. |
| Input Bias Current (max) | 1.5 nA | 1.5 nA | Low bias current is critical for high-impedance sensor interfaces; identical values preserve input loading behavior. |
| Common-Mode Rejection Ratio (min) | 80 dB | 80 dB | CMRR governs rejection of common-mode noise; equal values mean equivalent noise immunity. |
| Supply Voltage Range | ±2.3 V to ±18 V | ±2.3 V to ±18 V | Supply range must be compatible with the target system rails for the part to operate correctly. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Temperature range determines suitability for industrial versus commercial environments. |
| Package / Mounting | 8-SOIC, Surface Mount | 8-SOIC, Surface Mount | Package and mounting style must match the PCB footprint; the Z suffix denotes the RoHS-compliant SOIC variant. |
| RoHS Compliance | RoHS Compliant | Non-RoHS (legacy) | RoHS status affects regulatory compliance and solderability; the ARZ is the lead-free compliant version of the AR. |
Need help validating a replacement?
Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD8221ARZ | AD8221AR |
|---|---|---|
| Part Status | Active | Obsolete |
| Amplifier Type | Instrumentation | Instrumentation |
| Number of Circuits | 1 | 1 |
| Slew Rate | 2V/µs | 2V/µs |
| Current - Input Bias | 500 pA | 500 pA |
| Voltage - Input Offset | 60 µV | 60 µV |
| Supply Current | 900µA | 900µA |
| Current - Output / Channel | 18 mA | 18 mA |
| Voltage - Supply Span (Min) | - | 4.6 V |
| Voltage - Supply Span (Max) | - | 36 V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Mounting Type | Surface Mount | Surface Mount |
| Base Product Number | - | AD8221 |
| -3 dB Bandwidth | 825 kHz | 825 kHz |
| Voltage - Supply Span(Min) | 4.6 V | - |
| Voltage - Supply Span(Max) | 36 V | - |
Frequently asked questions
What is the difference between the AD8221ARZ and the AD8221AR?
The AD8221ARZ and AD8221AR are both gain-programmable instrumentation amplifiers from Analog Devices in an 8-lead SOIC package. The primary difference is the suffix: the "Z" in AD8221ARZ denotes RoHS-compliant lead-free construction, while the AD8221AR is the non-RoHS (leaded) version. Both share the same electrical specifications and functional performance.
Are the AD8221ARZ and AD8221AR electrically and functionally identical?
Yes. Both parts are the same AD8221 instrumentation amplifier core with identical gain range (1 to 1000), specified bandwidth, CMRR, offset voltage, and supply range (±2.3 V to ±18 V). The only documented distinction is the RoHS/lead-free status indicated by the "Z" suffix.
Can the AD8221ARZ be used as a drop-in replacement for the AD8221AR?
Yes, in most cases. Both are 8-lead SOIC devices with the same pinout and identical electrical specifications, so the AD8221ARZ can replace the AD8221AR on an existing PCB. The substitution should still be validated against the design's assembly and compliance requirements, particularly RoHS status.
Which part should be selected for a RoHS-compliant design?
The AD8221ARZ should be selected for RoHS-compliant assemblies, since the "Z" suffix designates lead-free, RoHS-compliant construction. The AD8221AR is the non-RoHS version and is not appropriate where RoHS compliance is mandated.
Do the AD8221ARZ and AD8221AR have the same package and pinout?
Yes. Both devices are offered in the same 8-lead SOIC (R-8) package with an identical pin configuration, including the gain-setting resistor pins, supply pins, reference pin, and output. This common package and pinout support interchangeability in PCB layout.
What are the key shared specifications of the AD8221ARZ and AD8221AR?
Both parts are gain-programmable instrumentation amplifiers with a gain range of 1 to 1000 set by a single external resistor, a supply range of ±2.3 V to ±18 V, high CMRR, low offset voltage, and low noise. They are specified for the same operating temperature range and share the same datasheet performance characteristics.
Does the "Z" suffix affect the electrical performance of the AD8221ARZ?
No. The "Z" suffix in the AD8221ARZ denotes RoHS-compliant, lead-free packaging and does not change the electrical specifications. The AD8221ARZ and AD8221AR share the same datasheet parameters for gain, bandwidth, CMRR, offset, and noise.