Part A
AD8656ARMZ
Công ty Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 7742 PCS
- Package
- MSOP-8
- Series
- Linear - Amplifiers - Instrumentation, OP Amps, Buffer Amps
Replacement verdict
Compatible functional replacement candidate
The AD8656ARMZ and AD8651ARM-R2 are both single-channel, low-noise CMOS operational amplifiers in the same 8-lead MSOP package, making the AD8656ARMZ a viable functional replacement candidate for the AD8651ARM-R2 in most designs. The AD8656ARMZ offers a higher gain-bandwidth product and lower voltage noise, though its slightly higher supply current and wider specified supply range should be validated against the target application's power budget and operating conditions before substitution.
Package Type
High match
Channel Count
High match
Supply Voltage Range
Validation required
Supply Current
Validation required
Parts at a glance
Part B
AD8651ARM-R2
Công ty Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 6636 PCS
- Package
- TSSOP-8
- Series
- Linear - Amplifiers - Instrumentation, 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 | AD8656ARMZ | AD8651ARM-R2 | Why it matters |
|---|---|---|---|
| Number of Amplifiers | 2 (Dual) | 1 (Single) | Channel count determines whether the part can directly replace the other in a circuit; a dual cannot substitute for a single without layout changes. |
| Input Offset Voltage (Max) | 250 µV | 500 µV | Lower offset voltage improves DC precision, which is critical for sensor and instrumentation signal chains. |
| Input Voltage Noise Density | 2.8 nV/√Hz | 5 nV/√Hz | Lower noise density yields better signal-to-noise ratio in low-level analog front ends. |
| Gain Bandwidth Product | 28 MHz | 50 MHz | GBW sets the achievable closed-loop bandwidth and affects stability margins in feedback designs. |
| Quiescent Current per Amplifier | 3.7 mA | 8 mA | Supply current impacts power budget and thermal design, especially in portable or dense systems. |
| Slew Rate | 11 V/µs | 22 V/µs | Slew rate limits large-signal bandwidth and affects distortion for fast, high-amplitude signals. |
| Package / Pin Count | 8-Lead MSOP | 8-Lead MSOP | Matching package and pin count enables drop-in board compatibility, though pinout function differs between single and dual. |
| Supply Voltage Range | 2.7 V to 5.5 V | 2.7 V to 5.5 V | Identical supply range allows operation from the same rails, supporting substitution in shared power architectures. |
| Operating Temperature Range | -40 °C to +125 °C | -40 °C to +125 °C | Equivalent temperature ratings ensure both parts meet the same environmental and reliability requirements. |
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 | AD8656ARMZ | AD8651ARM-R2 |
|---|---|---|
| Supplier | - | Analog Devices Inc.,Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| Amplifier Type | CMOS | Voltage Feedback |
| Number of Circuits | 2 | 1 |
| Output Type | Rail-to-Rail | Rail-to-Rail |
| Slew Rate | 11V/µs | 41V/µs |
| Gain Bandwidth Product | 28 MHz | 50 MHz |
| Current - Input Bias | 1 pA | 1 pA |
| Voltage - Input Offset | 50 µV | 100 µV |
| Supply Current | 3.7mA (x2 Channels) | 9.5mA |
| Current - Output / Channel | 220 mA | 40 mA |
| Voltage - Supply Span(Min) | 2.7 V | 2.7 V |
| Voltage - Supply Span(Max) | 5.5 V | 5.5 V |
| Operating Temperature | -40°C ~ 125°C | -40°C ~ 125°C |
| Mounting Type | Surface Mount | Surface Mount |
| Series | DigiTrim® | - |
Frequently asked questions
What are the key differences between the AD8656ARMZ and AD8651ARM-R2?
The AD8656ARMZ is a dual, low-noise, precision CMOS operational amplifier, while the AD8651ARM-R2 is a single, low-noise, precision CMOS operational amplifier. The AD8656ARMZ comes in an 8-lead MSOP package, whereas the AD8651ARM-R2 is supplied in an 8-lead MSOP as well but is a single-channel device. The AD8656ARMZ is typically supplied in tube or tray packaging, while the AD8651ARM-R2 is supplied on tape and reel (R2 suffix).
Are the AD8656ARMZ and AD8651ARM-R2 pin-compatible?
No. The AD8656ARMZ is a dual op-amp with both amplifiers' inputs and outputs assigned to the 8 MSOP pins, while the AD8651ARM-R2 is a single op-amp with a different pin function assignment (including dedicated null and disable pins). They are not drop-in replacements for each other despite sharing the same 8-lead MSOP footprint.
What are the supply voltage and bandwidth specifications for these amplifiers?
Both the AD8656ARMZ and AD8651ARM-R2 operate from a single supply of 2.7 V to 5.5 V. The AD8656ARMZ has a gain bandwidth product of 28 MHz, and the AD8651ARM-R2 has a gain bandwidth product of 50 MHz, per the respective Analog Devices datasheets.
How do the noise characteristics of the AD8656ARMZ and AD8651ARM-R2 compare?
Both devices are low-noise CMOS amplifiers. The AD8656ARMZ specifies a voltage noise density of 2.7 nV/√Hz at 1 kHz, while the AD8651ARM-R2 specifies 5 nV/√Hz at 1 kHz. The AD8656ARMZ therefore offers lower input voltage noise density than the AD8651ARM-R2.
Can the AD8651ARM-R2 be used to replace one channel of the AD8656ARMZ in an existing design?
Not directly. Although both are precision CMOS op-amps in 8-lead MSOP packages, the pinouts differ, and the AD8651ARM-R2 is a single-channel device with different bandwidth and noise specifications. A replacement requires verifying pin functions, gain bandwidth, noise, and stability against the AD8656ARMZ datasheet and the target circuit requirements.
What packaging options are available for the AD8656ARMZ and AD8651ARM-R2?
The AD8656ARMZ is offered in an 8-lead MSOP (RM suffix) package, typically in tube or tray quantities. The AD8651ARM-R2 is also offered in an 8-lead MSOP package but is supplied on tape and reel (R2 suffix) for automated assembly. Both are RoHS-compliant per Analog Devices documentation.
What are the input offset voltage specifications for these two amplifiers?
The AD8656ARMZ specifies a maximum input offset voltage of 250 µV. The AD8651ARM-R2 specifies a maximum input offset voltage of 500 µV. Both are precision CMOS amplifiers suitable for DC-accurate signal conditioning, with the AD8656ARMZ offering tighter offset voltage.