Part A
AD8420ARMZ
Компания Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 1829 ПКС
- Package
- MSOP-8
- Series
- Линейные - Усилетели - Приборы, ОП Усилетели, Буферные Усилетели
Replacement verdict
Compatible functional replacement candidate
The AD8420ARMZ and AD8422BRMZ-RL are both precision instrumentation amplifiers in the same 8-lead MSOP package, making them a viable functional replacement candidate in many designs. However, the AD8422BRMZ-RL offers substantially higher bandwidth and a wider supply range, while the AD8420ARMZ provides a lower minimum supply voltage and lower quiescent current. Designers should validate gain-setting resistor networks, supply headroom, and dynamic response requirements before substituting one for the other.
Package Type
High match
Supply Voltage Range
Validation required
Bandwidth
Validation required
Input Offset Voltage
Validation required
Parts at a glance
Part B
AD8422BRMZ-RL
Компания Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 3392 ПКС
- Package
- TSSOP-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 | AD8420ARMZ | AD8422BRMZ-RL | Why it matters |
|---|---|---|---|
| Number of Channels | 1 | 1 | Both are single-channel instrumentation amplifiers, so channel count is functionally equivalent. |
| Supply Voltage Range | 2.7 V to 36 V (single supply) | 4.6 V to 36 V (single supply) | The AD8420 supports lower supply voltages, enabling operation in low-voltage systems where the AD8422 cannot be used. |
| Input Offset Voltage (max) | 250 µV | 70 µV | Lower offset voltage improves DC accuracy; the AD8422 offers better precision for low-level signal measurement. |
| Gain Bandwidth Product | 1.1 MHz | 2.2 MHz | Higher bandwidth allows the AD8422 to handle faster signals and higher gains without bandwidth limitation. |
| Input Voltage Noise (1 kHz) | 27 nV/√Hz | 8 nV/√Hz | Lower input noise improves signal-to-noise ratio; the AD8422 is better suited for low-noise precision applications. |
| CMRR (G=100, DC) | 100 dB | 120 dB | Higher common-mode rejection reduces interference from common-mode signals; the AD8422 provides superior rejection. |
| Quiescent Current (typ) | 1.1 mA | 0.3 mA | Lower quiescent current extends battery life; the AD8422 is more power-efficient for portable designs. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +125 °C | The wider temperature range of the AD8422 allows use in harsher environments and industrial applications. |
| Package | 8-Lead MSOP | 8-Lead MSOP | Identical package and pinout enable drop-in replacement on the same PCB footprint. |
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 | AD8420ARMZ | AD8422BRMZ-RL |
|---|---|---|
| Supplier | - | Analog Devices Inc. |
| Part Status | Active | Active |
| Amplifier Type | Instrumentation | Instrumentation |
| Number of Circuits | 1 | 1 |
| Output Type | Rail-to-Rail | Rail-to-Rail |
| Slew Rate | 1V/µs | 0.8V/µs |
| -3 dB Bandwidth | 250 kHz | 2.2 MHz |
| Current - Input Bias | 20 nA | 200 pA |
| Voltage - Input Offset | 250 µV | 50 µV |
| Supply Current | 85µA | 300µA |
| Current - Output / Channel | 10 mA | 20 mA |
| Voltage - Supply Span(Min) | 2.7 V | 4.6 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 |
Frequently asked questions
What are the primary differences between the AD8420ARMZ and AD8422BRMZ-RL?
The AD8420ARMZ is a micropower instrumentation amplifier with a maximum supply current of 85 µA and a gain bandwidth product of 2.5 MHz, supplied in an 8-lead MSOP package. The AD8422BRMZ-RL is a high precision, low power instrumentation amplifier with a maximum supply current of 300 µA, a gain bandwidth product of 2.2 MHz, and significantly lower offset voltage (maximum 70 µV for the B grade) and offset drift (0.3 µV/°C typical). The AD8422BRMZ-RL is supplied in an 8-lead MSOP and is provided in tape-and-reel packaging.
Are the AD8420ARMZ and AD8422BRMZ-RL pin-compatible?
Both devices are offered in an 8-lead MSOP package, and their pinouts are functionally equivalent (gain-setting resistor pins, supply pins, reference pin, and output). However, designers must verify the exact pin configuration and any package-specific thermal or layout considerations against the respective manufacturer datasheets before substituting one for the other on an existing PCB.
Which device offers lower power consumption for battery-powered applications?
The AD8420ARMZ is the lower-power option, with a maximum supply current of 85 µA compared to 300 µA maximum for the AD8422BRMZ-RL. For applications where quiescent current is the dominant constraint, the AD8420ARMZ is preferable, while the AD8422BRMZ-RL trades higher supply current for improved DC precision.
How do the offset voltage and drift specifications compare?
The AD8422BRMZ-RL (B grade) specifies a maximum input offset voltage of 70 µV with a typical offset drift of 0.3 µV/°C, making it suitable for high-precision DC measurement. The AD8420ARMZ specifies a maximum input offset voltage of 250 µV with a typical offset drift of 1 µV/°C. The AD8422BRMZ-RL therefore provides tighter DC accuracy in precision signal-conditioning applications.
What are the gain bandwidth and noise characteristics of each device?
The AD8420ARMZ has a gain bandwidth product of 2.5 MHz and a typical input voltage noise of 55 nV/√Hz at 1 kHz. The AD8422BRMZ-RL has a gain bandwidth product of 2.2 MHz and a typical input voltage noise of 8 nV/√Hz at 1 kHz. The AD8422BRMZ-RL offers substantially lower input-referred noise, which benefits low-level signal amplification.
What supply voltage ranges do these instrumentation amplifiers support?
The AD8420ARMZ operates from a single supply of 2.7 V to 36 V or dual supplies of ±1.35 V to ±18 V. The AD8422BRMZ-RL operates from a single supply of 4.5 V to 36 V or dual supplies of ±2.25 V to ±18 V. The AD8420ARMZ supports a lower minimum supply voltage, which can be advantageous in low-voltage systems.
What is the difference in packaging and ordering format?
The AD8420ARMZ is supplied in an 8-lead MSOP tube or tray format (the "ARMZ" suffix denotes the MSOP package). The AD8422BRMZ-RL is supplied in an 8-lead MSOP in tape-and-reel format (the "-RL" suffix denotes tape-and-reel packaging), which is suited to high-volume automated assembly. Both use the same 8-lead MSOP body, but the ordering quantity and packaging format differ.
Which device is better suited for high-precision bridge sensor applications?
The AD8422BRMZ-RL is generally better suited for high-precision bridge sensor applications due to its lower maximum offset voltage (70 µV), lower offset drift (0.3 µV/°C typical), and lower input voltage noise (8 nV/√Hz typical). The AD8420ARMZ remains a viable choice where micropower operation is the primary requirement and the looser offset and noise specifications are acceptable.