Part A
AD8221ARM
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 2853 PCS
- Package
- TSSOP-8
- Series
- Linear - Amplificadores - Instrumentação, OP Amps, Buffer Amps
Replacement verdict
Compatible functional replacement candidate
The AD822ARMZ-R2 is a functionally compatible replacement candidate for the AD8221ARM, sharing the same instrumentation amplifier function, SOIC-8 package, and single-supply operating range, though validation is required for gain-setting configuration and bandwidth-dependent applications due to differences in gain range and closed-loop bandwidth.
Amplifier Function
High match
Package Type
High match
Gain Range
Validation required
Bandwidth
Validation required
Parts at a glance
Part B
AD822ARMZ-R2
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 9829 PCS
- Package
- TSSOP-8
- Series
- Linear - Amplificadores - Instrumentação, 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 | AD8221ARM | AD822ARMZ-R2 | Why it matters |
|---|---|---|---|
| Amplifier Type | Instrumentation Amplifier | General Purpose Amplifier (Dual) | Determines the fundamental function; an instrumentation amp is optimized for differential signal acquisition, while a general-purpose dual op-amp serves different circuit roles. |
| Number of Channels | 1 | 2 | Channel count affects how many signal paths can be processed per package and impacts board layout and cost. |
| Input Offset Voltage (Max) | 60 µV | 800 µV | Lower offset voltage yields higher DC accuracy; a large difference means the parts are not directly interchangeable in precision applications. |
| Gain Bandwidth Product | 825 kHz (G=1) | 1.9 MHz | Bandwidth determines the maximum signal frequency the amplifier can handle with acceptable gain, affecting dynamic performance. |
| Supply Voltage Range | ±2.3 V to ±18 V | ±1.5 V to ±15 V | The usable supply range must match the system rails; differing ranges constrain where each part can be safely operated. |
| Input Bias Current (Typ) | 0.5 nA | 2 pA | Bias current affects error in high-impedance sources; the JFET-input AD822 has far lower bias current than the bipolar AD8221. |
| Package / Mounting | 8-Lead MSOP (Surface Mount) | 8-Lead SOIC (Surface Mount) | Footprint and package type must match the PCB land pattern; different packages are not drop-in compatible. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Both share the same industrial temperature range, so thermal environment compatibility is equivalent. |
| Supply Current per Amplifier (Typ) | 1 mA | 0.9 mA | Quiescent current impacts power budget; similar values mean comparable power consumption in low-power designs. |
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 | AD8221ARM | AD822ARMZ-R2 |
|---|---|---|
| Supplier | - | Analog Devices Inc. |
| Part Status | Obsolete | Obsolete |
| Amplifier Type | Instrumentation | General Purpose |
| Number of Circuits | 1 | 2 |
| Output Type | - | Rail-to-Rail |
| Slew Rate | 2V/µs | 3V/µs |
| Gain Bandwidth Product | - | 1.9 MHz |
| -3 dB Bandwidth | 825 kHz | 1.9 MHz |
| Current - Input Bias | 500 pA | 2 pA |
| Voltage - Input Offset | 60 µV | 400 µV |
| Supply Current | 900µA | 1.24mA |
| Current - Output / Channel | 18 mA | 20 mA |
| Voltage - Supply Span(Min) | 4.6 V | 5 V |
| Voltage - Supply Span(Max) | 36 V | 30 V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the fundamental differences between the AD8221ARM and the AD822ARMZ-R2?
The AD8221ARM is a high-performance instrumentation amplifier from Analog Devices supplied in an 8-lead MSOP (RM) package. The AD822ARMZ-R2 is a dual, low-power operational amplifier supplied in an 8-lead SOIC (R) package on a 7-inch reel (R2). They are functionally different devices: the AD8221 is a single instrumentation amplifier, while the AD822 is a dual op-amp.
Can the AD8221ARM and AD822ARMZ-R2 be substituted for each other in a design?
No. The AD8221ARM is a single instrumentation amplifier, whereas the AD822ARMZ-R2 is a dual operational amplifier. Their internal topologies, pin functions, and intended applications differ, so they are not pin-compatible or functionally interchangeable.
What are the package and pinout differences between these two parts?
The AD8221ARM uses an 8-lead MSOP package with instrumentation amplifier pin functions (including gain-setting resistor pins). The AD822ARMZ-R2 uses an 8-lead SOIC package with dual op-amp pin functions (two amplifiers sharing power pins). The pinouts and PCB land patterns are not compatible.
How do the supply voltage and power consumption characteristics compare?
The AD8221ARM operates on dual supplies typically from ±2.3 V to ±18 V and draws a low supply current suitable for precision instrumentation. The AD822ARMZ-R2 is a dual op-amp designed for low-power operation on single or dual supplies. Exact quiescent current and supply range should be confirmed from the respective Analog Devices datasheets before design use.
Which part is better suited for precision sensor signal conditioning?
The AD8221ARM is specifically designed as a high-performance instrumentation amplifier with excellent common-mode rejection and low offset, making it well suited for precision sensor signal conditioning. The AD822ARMZ-R2 is a general-purpose dual op-amp and is not an instrumentation amplifier, so it is less appropriate for demanding precision bridge or sensor front ends.
What does the "R2" suffix on the AD822ARMZ-R2 indicate?
The "R2" suffix denotes a tape-and-reel packaging quantity of 2,000 units on a 7-inch reel, as defined by Analog Devices ordering conventions. The "Z" indicates a lead-free (RoHS-compliant) package. The AD8221ARM is supplied in tube or reel form depending on the specific ordering code.
Are both parts RoHS compliant?
The AD822ARMZ-R2 carries the "Z" suffix, which denotes a lead-free, RoHS-compliant package per Analog Devices ordering nomenclature. RoHS status for the AD8221ARM depends on the specific ordering code; designers should verify the exact part number against the manufacturer's product page or datasheet before assuming compliance.