Part A
AD8422ARZ
Компания Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 3872 ПКС
- Package
- SOIC-8
- Series
- Линейные - Усилетели - Приборы, ОП Усилетели, Буферные Усилетели
Replacement verdict
Compatible functional replacement candidate
The AD8422ARZ and AD8421ARZ-RL are both precision instrumentation amplifiers in the same SOIC-8 package with identical pinout, making them a viable functional replacement candidate. However, the AD8421ARZ-RL offers significantly higher bandwidth and faster settling, while the AD8422ARZ provides lower supply current and wider supply range. Designers should validate gain-setting resistor values, noise performance, and dynamic response against their specific application requirements before substituting.
Package Type
High match
Pin Configuration
High match
Bandwidth
Validation required
Supply Current
Validation required
Parts at a glance
Part B
AD8421ARZ-RL
Компания Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 4538 ПКС
- Package
- SOIC-8
- Series
- Линейные - Усилетели - Приборы, ОП Усилетели, Буферные Усилетели
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD8422ARZ | AD8421ARZ-RL | Why it matters |
|---|---|---|---|
| Gain Bandwidth Product (GBP) | 1 MHz | 10 MHz | Higher bandwidth allows the amplifier to handle faster signals and wider frequency content, which is critical for high-speed signal conditioning. |
| Input Voltage Noise (1 kHz) | 8 nV/√Hz | 3 nV/√Hz | Lower input voltage noise improves the signal-to-noise ratio for low-level signal amplification, which is essential in precision measurement applications. |
| Input Offset Voltage (max) | 70 µV | 60 µV | Lower offset voltage reduces DC error at the output, improving accuracy in precision instrumentation and sensor interface circuits. |
| Supply Current per Amplifier | 300 µA | 2.3 mA | Lower supply current is important for battery-powered and portable applications where power consumption directly affects runtime. |
| CMRR (DC to 60 Hz, G=1000) | 120 dB | 134 dB | Higher common-mode rejection ratio suppresses unwanted common-mode signals, which is critical for extracting small differential signals in noisy environments. |
| Input Bias Current (max) | 1 nA | 0.5 nA | Lower input bias current minimizes errors when interfacing with high-impedance sources such as sensors and transducers. |
| Slew Rate | 0.8 V/µs | 35 V/µs | Higher slew rate enables the amplifier to respond to fast transients and large signal swings without distortion, important for dynamic signal processing. |
| Supply Voltage Range | 4.6 V to 36 V | 5 V to 30 V | A wider supply range provides flexibility in system design and compatibility with a broader set of power rails. |
| Operating Temperature Range | -40°C to +85°C | -40°C to +125°C | A wider operating temperature range allows use in harsh environments and industrial applications requiring extended thermal tolerance. |
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 | AD8422ARZ | AD8421ARZ-RL |
|---|---|---|
| Supplier | - | Analog Devices Inc. |
| Part Status | Active | Active |
| Amplifier Type | Instrumentation | Instrumentation |
| Number of Circuits | 1 | 1 |
| Slew Rate | 0.8V/µs | 35V/µs |
| -3 dB Bandwidth | 2.2 MHz | 10 MHz |
| Current - Input Bias | 500 pA | 1 nA |
| Voltage - Input Offset | 60 µV | 60 µV |
| Supply Current | 300µA | 2mA |
| Current - Output / Channel | 20 mA | 65 mA |
| Voltage - Supply Span(Min) | 4.6 V | 5 V |
| Voltage - Supply Span(Max) | 36 V | 36 V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Mounting Type | Surface Mount | Surface Mount |
| Output Type | Rail-to-Rail | - |
Frequently asked questions
What are the primary differences between the AD8422ARZ and AD8421ARZ-RL?
The AD8422ARZ is an instrumentation amplifier with a supply range of ±2.3 V to ±18 V (or 4.6 V to 36 V single-supply), a gain bandwidth of 2.2 MHz at G = 1, and a maximum input offset voltage of 70 µV. The AD8421ARZ-RL is a lower-noise instrumentation amplifier with a supply range of ±2.25 V to ±18 V (or 4.5 V to 36 V single-supply), a gain bandwidth of 10 MHz at G = 1, and a maximum input offset voltage of 60 µV. The AD8421ARZ-RL is supplied in tape-and-reel packaging, while the AD8422ARZ is supplied in a tube.
Are the AD8422ARZ and AD8421ARZ-RL pin-compatible?
Yes. Both devices are offered in an 8-lead SOIC package with the same pinout: -IN, +IN, -VS, +VS, and the RG pins for gain setting. This allows them to share the same PCB footprint, but electrical differences must still be validated before substitution.
How do the noise specifications of the AD8422ARZ and AD8421ARZ-RL compare?
The AD8421ARZ-RL has a lower input voltage noise density of 3 nV/√Hz at 1 kHz, while the AD8422ARZ specifies 8 nV/√Hz at 1 kHz. For low-level signal applications where noise is critical, the AD8421ARZ-RL offers better noise performance.
What is the gain bandwidth product of each device?
The AD8422ARZ has a gain bandwidth of 2.2 MHz at G = 1, whereas the AD8421ARZ-RL has a gain bandwidth of 10 MHz at G = 1. The AD8421ARZ-RL therefore provides wider bandwidth for higher-frequency signal conditioning.
What are the supply voltage ranges for the AD8422ARZ and AD8421ARZ-RL?
The AD8422ARZ operates from ±2.3 V to ±18 V dual supply or 4.6 V to 36 V single supply. The AD8421ARZ-RL operates from ±2.25 V to ±18 V dual supply or 4.5 V to 36 V single supply. Both support a wide range of industrial and instrumentation supply rails.
How do the input offset voltage specifications differ?
The AD8422ARZ specifies a maximum input offset voltage of 70 µV, while the AD8421ARZ-RL specifies a maximum input offset voltage of 60 µV. Both are suitable for precision applications, with the AD8421ARZ-RL offering a slightly tighter offset limit.
What packaging options are available for these two parts?
The AD8422ARZ is supplied in an 8-lead SOIC package in tube form. The AD8421ARZ-RL is supplied in an 8-lead SOIC package in tape-and-reel form, making it suitable for automated high-volume assembly.
Can the AD8422ARZ and AD8421ARZ-RL be used interchangeably in a design?
They are pin-compatible and share the same package, but they differ in noise, bandwidth, and offset specifications. Interchangeability depends on whether the design can tolerate the AD8422ARZ's higher noise and lower bandwidth or the AD8421ARZ-RL's different supply and offset limits. Substitution should be validated against the specific application requirements and manufacturer datasheets.