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 AD8226BRZ-RL is a viable functional replacement candidate for the AD8221ARZ in many instrumentation amplifier applications, sharing the same SOIC-8 footprint and comparable gain-bandwidth performance. However, the AD8226 offers a wider supply range and rail-to-rail output, while the AD8221 provides superior CMRR and lower noise for precision bridge and sensor signal conditioning. Designers should validate gain error, offset drift, and common-mode rejection against their specific application requirements before substituting.
Package Type
High match
Supply Voltage Range
High match
Gain Bandwidth Product
Validation required
Common-Mode Rejection Ratio
Validation required
Parts at a glance
Part B
AD8226BRZ-RL
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 3813 PCS
- Package
- SOIC-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 | AD8221ARZ | AD8226BRZ-RL | Why it matters |
|---|---|---|---|
| Number of Amplifiers | 1 | 1 | Both are single instrumentation amplifiers, so channel count is equivalent for substitution. |
| Gain Range (Min) | 1 | 1 | Both support unity gain, allowing use as a simple difference amplifier. |
| Gain Range (Max) | 1000 | 1000 | Maximum settable gain is identical, so high-gain signal conditioning is interchangeable. |
| Input Offset Voltage (Max) | 60 µV | 150 µV | Lower offset in AD8221ARZ gives better DC accuracy; AD8226BRZ-RL has higher offset, affecting precision in low-level signal applications. |
| Input Bias Current (Typ) | 0.5 nA | 0.5 nA | Low bias current is critical for high-impedance sensor interfaces; both are equivalent here. |
| Gain Bandwidth Product | 825 kHz | 1.5 MHz | AD8226BRZ-RL offers wider bandwidth, enabling higher-frequency signal processing than AD8221ARZ. |
| CMRR (Min, G=100) | 110 dB | 100 dB | Higher CMRR in AD8221ARZ rejects common-mode noise better, improving accuracy in noisy environments. |
| Supply Voltage Range | ±2.3 V to ±18 V | ±1.35 V to ±18 V | AD8226BRZ-RL operates at lower supply voltages, making it suitable for low-voltage or battery-powered systems. |
| Supply Current (Typ) | 1.0 mA | 0.75 mA | Lower quiescent current in AD8226BRZ-RL benefits power-sensitive designs. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +125 °C | AD8226BRZ-RL supports higher ambient temperatures, suitable for harsher industrial environments. |
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 | AD8226BRZ-RL |
|---|---|---|
| Supplier | - | Analog Devices Inc. |
| Part Status | Active | Obsolete |
| Amplifier Type | Instrumentation | Instrumentation |
| Number of Circuits | 1 | 1 |
| Output Type | - | Rail-to-Rail |
| Slew Rate | 2V/µs | 0.6V/µs |
| -3 dB Bandwidth | 825 kHz | 1.5 MHz |
| Current - Input Bias | 500 pA | 20 nA |
| Voltage - Input Offset | 60 µV | 50 µV |
| Supply Current | 900µA | 350µA |
| Current - Output / Channel | 18 mA | 13 mA |
| Voltage - Supply Span(Min) | 4.6 V | 2.2 V |
| Voltage - Supply Span(Max) | 36 V | 36 V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 125°C |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the primary functional differences between the AD8221ARZ and AD8226BRZ-RL?
The AD8221ARZ is a high-performance instrumentation amplifier with a fixed gain range of 1 to 1000, featuring a typical CMRR of 90 dB at G=1 and a bandwidth of 825 kHz at G=1. The AD8226BRZ-RL is a wide-supply-range instrumentation amplifier with a gain range of 1 to 1000, a typical CMRR of 80 dB at G=1, and a bandwidth of 1.5 MHz at G=1. The AD8221ARZ is optimized for higher precision and lower noise, while the AD8226BRZ-RL offers a wider supply voltage range and rail-to-rail output.
Are the AD8221ARZ and AD8226BRZ-RL pin-compatible?
No. The AD8221ARZ is packaged in an 8-lead SOIC (R-8) with a standard instrumentation amplifier pinout. The AD8226BRZ-RL is packaged in an 8-lead SOIC (R-8) but has a different pin configuration, including a dedicated REF pin arrangement and rail-to-rail output stage. Direct PCB substitution is not possible without layout changes.
What are the supply voltage ranges for each device?
The AD8221ARZ operates on a dual supply of ±2.3 V to ±18 V (or single supply 4.6 V to 36 V). The AD8226BRZ-RL operates on a dual supply of ±1.35 V to ±18 V (or single supply 2.7 V to 36 V), allowing lower-voltage operation.
How do the input offset voltage and drift compare?
The AD8221ARZ has a maximum input offset voltage of 60 µV and a typical offset drift of 0.3 µV/°C. The AD8226BRZ-RL has a maximum input offset voltage of 150 µV and a typical offset drift of 0.5 µV/°C. The AD8221ARZ offers better DC precision.
What is the gain-setting method for each part?
Both devices use a single external resistor to set gain from 1 to 1000. The gain equation for the AD8221ARZ is G = 1 + (49.4 kΩ / R_G). The gain equation for the AD8226BRZ-RL is G = 1 + (49.4 kΩ / R_G). The resistor value and tolerance requirements are similar, but the AD8221ARZ specifies tighter gain error and nonlinearity.
Which device is better suited for low-voltage or battery-powered applications?
The AD8226BRZ-RL is better suited for low-voltage applications because it operates down to ±1.35 V dual supply (2.7 V single supply) and features a rail-to-rail output. The AD8221ARZ requires a minimum ±2.3 V dual supply (4.6 V single supply) and has a output swing that is not rail-to-rail.
How do the bandwidth and slew rate compare?
At G=1, the AD8221ARZ has a typical -3 dB bandwidth of 825 kHz and a slew rate of 2 V/µs. The AD8226BRZ-RL has a typical -3 dB bandwidth of 1.5 MHz and a slew rate of 0.8 V/µs. The AD8226BRZ-RL provides wider small-signal bandwidth, while the AD8221ARZ has a higher slew rate.
What are the operating temperature ranges and package options?
Both devices are specified over the industrial temperature range of −40°C to +85°C. The AD8221ARZ is available in an 8-lead SOIC (R-8) package. The AD8226BRZ-RL is available in an 8-lead SOIC (R-8) package and is supplied in tape and reel format (RL suffix).