Part A
AD8429ARZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 7143 Stückzahl
- Package
- SOIC-8
- Series
- Linear-Verstärker.Instrumentation, OP-Verstärker, Pufferverstärker
Replacement verdict
Compatible functional replacement candidate
The AD8429ARZ and AD8422ARZ-RL are both precision instrumentation amplifiers in the same SOIC-8 package and pinout, making them functionally interchangeable in many designs. However, the AD8429ARZ offers substantially lower voltage noise and higher bandwidth, while the AD8422ARZ-RL provides lower power consumption and wider supply range flexibility. Designers should validate gain-setting resistor values, noise budget, and supply headroom before substituting one for the other in noise-critical or power-sensitive applications.
Package and Pinout
High match
Supply Voltage Range
High match
Voltage Noise Density
Validation required
Gain Bandwidth Product
Validation required
Parts at a glance
Part B
AD8422ARZ-RL
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 9390 Stückzahl
- Package
- SOIC-8
- Series
- Linear-Verstärker.Instrumentation, OP-Verstärker, Pufferverstärker
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD8429ARZ | AD8422ARZ-RL | Why it matters |
|---|---|---|---|
| Number of Channels | 1 | 1 | Both are single-channel instrumentation amplifiers, so channel count is functionally equivalent. |
| Gain Bandwidth Product (GBW) | 15 MHz | 2.2 MHz | Higher GBW allows the AD8429 to handle wider-bandwidth signals at high gain, affecting dynamic performance. |
| Input Voltage Noise (1 kHz) | 1 nV/√Hz | 8 nV/√Hz | Lower input noise improves signal-to-noise ratio for low-level sensor signals; the AD8429 is significantly quieter. |
| Input Offset Voltage (max) | 50 µV | 70 µV | Lower offset reduces DC error at the output, important for precision measurement applications. |
| Supply Voltage Range | ±4 V to ±18 V | ±2.3 V to ±18 V | The AD8422 supports lower supply voltages, enabling use in low-voltage or battery-powered systems where the AD8429 cannot operate. |
| Quiescent Supply Current | 6.5 mA | 0.3 mA | The AD8422 draws far less current, making it preferable for power-sensitive designs. |
| CMRR (G=100, DC to 60 Hz) | 126 dB | 120 dB | Higher common-mode rejection suppresses interference; the AD8429 offers slightly better rejection. |
| Operating Temperature Range | -40 °C to +125 °C | -40 °C to +85 °C | The AD8429 supports a wider temperature range, suitable for harsher environments. |
| Package | 8-Lead SOIC | 8-Lead SOIC | Identical package and pinout allow drop-in board compatibility between the two parts. |
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Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD8429ARZ | AD8422ARZ-RL |
|---|---|---|
| Supplier | - | Analog Devices Inc. |
| Part Status | Active | Active |
| Amplifier Type | Instrumentation | Instrumentation |
| Number of Circuits | 1 | 1 |
| Output Type | - | Rail-to-Rail |
| Slew Rate | 22V/µs | 0.8V/µs |
| -3 dB Bandwidth | 15 MHz | 2.2 MHz |
| Current - Input Bias | 300 nA | 500 pA |
| Voltage - Input Offset | 150 µV | 60 µV |
| Supply Current | 6.7mA | 300µA |
| Current - Output / Channel | 35 mA | 20 mA |
| Voltage - Supply Span(Min) | 8 V | 4.6 V |
| Voltage - Supply Span(Max) | 36 V | 36 V |
| Operating Temperature | -40°C ~ 125°C | -40°C ~ 85°C |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the primary differences between the AD8429ARZ and AD8422ARZ-RL?
The AD8429ARZ is a low-noise instrumentation amplifier optimized for high gain and low noise (1 nV/√Hz) with a gain range of 1 to 10,000, while the AD8422ARZ-RL is a high-precision, low-power instrumentation amplifier with lower power consumption and a gain range of 1 to 1,000. The AD8429ARZ is supplied in an 8-lead SOIC package, and the AD8422ARZ-RL is supplied in an 8-lead SOIC package in tape and reel format.
Are the AD8429ARZ and AD8422ARZ-RL pin-compatible?
Both devices are offered in 8-lead SOIC packages with the same pinout for the instrumentation amplifier function, but designers must verify the gain-setting resistor connections and reference pin behavior against the respective datasheets before considering a direct replacement.
Which device offers lower input voltage noise?
The AD8429ARZ specifies an input voltage noise of 1 nV/√Hz at 1 kHz, which is lower than the AD8422ARZ-RL, making the AD8429ARZ preferable for low-noise signal acquisition applications.
How do the power consumption specifications compare?
The AD8422ARZ-RL is designed for lower power operation with a typical supply current of approximately 300 µA, whereas the AD8429ARZ draws a higher supply current, making the AD8422ARZ-RL more suitable for battery-powered or power-sensitive designs.
What is the gain range of each device?
The AD8429ARZ supports gains from 1 to 10,000 using a single external resistor, while the AD8422ARZ-RL supports gains from 1 to 1,000. Designs requiring gains above 1,000 should use the AD8429ARZ.
Which device is better suited for high-precision DC measurements?
The AD8422ARZ-RL offers lower offset voltage and offset voltage drift, making it better suited for high-precision DC measurements, while the AD8429ARZ is optimized for low-noise AC signal amplification.
What are the supply voltage requirements for these devices?
Both the AD8429ARZ and AD8422ARZ-RL operate from dual supplies of ±4 V to ±18 V (or single supply of 8 V to 36 V), allowing use in a wide range of industrial and instrumentation systems.
What package and ordering options are available?
The AD8429ARZ is supplied in an 8-lead SOIC package in tube form, while the AD8422ARZ-RL is supplied in an 8-lead SOIC package in tape and reel format for automated assembly.