Part A
AD8651ARMZ
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 6670 PCS
- Package
- MSOP-8
- Series
- Amplificateurs linéaires - instruments, amplificateurs opérationnels, amplificateurs tampons
Replacement verdict
Compatible functional replacement candidate
The AD8656ARMZ and AD8651ARMZ are both single-channel, low-noise, precision CMOS operational amplifiers in the same 8-lead MSOP package with identical pinout, making the AD8656ARMZ a strong functional replacement candidate for the AD8651ARMZ in most designs. The primary differentiator is the supply voltage range: the AD8656ARMZ supports a wider 2.7 V to 5.5 V supply, while the AD8651ARMZ is specified for 5 V operation, so designs operating below 5 V should be validated against the AD8651ARMZ requirements before substitution.
Package and Pinout
High match
Channel Count
High match
Supply Voltage Range
Validation required
Amplifier Type
High match
Parts at a glance
Part B
AD8656ARMZ
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 7742 PCS
- Package
- MSOP-8
- Series
- Amplificateurs linéaires - instruments, amplificateurs opérationnels, amplificateurs tampons
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 | AD8651ARMZ | Why it matters |
|---|---|---|---|
| Number of Amplifiers | 2 (Dual) | 1 (Single) | Channel count determines whether the part can serve dual-channel signal paths; a single cannot directly replace a dual without redesign. |
| Input Offset Voltage (Max) | 250 µV | 500 µV | Lower offset improves DC accuracy in precision signal chains; the dual part offers tighter guaranteed offset. |
| Input Voltage Noise Density | 2.7 nV/√Hz | 5 nV/√Hz | Lower noise density benefits low-level signal amplification; the dual part is roughly half the noise of the single. |
| Gain Bandwidth Product | 28 MHz | 50 MHz | GBW sets the achievable closed-loop bandwidth; the single part supports higher-frequency signals. |
| Slew Rate | 11 V/µs | 22 V/µs | Slew rate limits large-signal response and settling; the single part handles faster transients. |
| Supply Current per Amplifier (Typ) | 2.3 mA | 3.5 mA | Quiescent current affects power budget; the dual part is more power-efficient per amplifier. |
| Supply Voltage Range | 2.7 V to 5.5 V | 2.7 V to 5.5 V | Identical supply range means both operate from the same rails, easing substitution in the power domain. |
| Rail-to-Rail Input/Output | Yes (RRIO) | Yes (RRIO) | RRIO capability maximizes dynamic range on low-voltage supplies; both share this behavior. |
| Package | 8-Lead MSOP | 8-Lead MSOP | Same package footprint allows drop-in board placement, though pin functions differ between single and dual. |
| Operating Temperature Range | -40 °C to +125 °C | -40 °C to +125 °C | Identical industrial temperature rating supports use in the same environmental conditions. |
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 | AD8651ARMZ | AD8656ARMZ |
|---|---|---|
| Series | DigiTrim® | DigiTrim® |
| Part Status | Active | Active |
| Amplifier Type | Voltage Feedback | CMOS |
| Number of Circuits | 1 | 2 |
| Output Type | Rail-to-Rail | Rail-to-Rail |
| Slew Rate | 41V/µs | 11V/µs |
| Gain Bandwidth Product | 50 MHz | 28 MHz |
| Current - Input Bias | 1 pA | 1 pA |
| Voltage - Input Offset | 100 µV | 50 µV |
| Supply Current | 9.5mA | 3.7mA (x2 Channels) |
| Current - Output / Channel | 40 mA | 220 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 |
Frequently asked questions
What are the key differences between the AD8656ARMZ and AD8651ARMZ operational amplifiers?
The AD8656ARMZ is a dual, low-noise, precision CMOS operational amplifier, while the AD8651ARMZ is a single-channel version of the same amplifier family. Both share similar voltage noise density (approximately 4.5 nV/√Hz at 1 kHz), rail-to-rail input and output, and a 28 MHz gain bandwidth product, but differ in channel count and package pinout.
Are the AD8656ARMZ and AD8651ARMZ pin-compatible?
No. The AD8656ARMZ is a dual op-amp in an 8-lead MSOP package, while the AD8651ARMZ is a single op-amp in an 8-lead MSOP package. Although both use the same package outline, the pin functions differ because one device contains two amplifiers and the other contains one, so they are not drop-in replacements for each other.
What is the supply voltage range for the AD8656ARMZ and AD8651ARMZ?
Both devices operate from a single supply of 2.7 V to 5.5 V, or from dual supplies of ±1.35 V to ±2.75 V, as specified in the Analog Devices datasheets.
What is the gain bandwidth product of the AD8656ARMZ and AD8651ARMZ?
Both the AD8656ARMZ and AD8651ARMZ feature a gain bandwidth product of 28 MHz, according to the manufacturer datasheets.
What is the input voltage noise density of the AD8656ARMZ and AD8651ARMZ?
Both devices specify a low input voltage noise density of approximately 4.5 nV/√Hz at 1 kHz, making them suitable for precision and low-noise signal conditioning applications.
Can the AD8651ARMZ be used as a replacement for one channel of the AD8656ARMZ in a dual-op-amp design?
Functionally, one channel of the AD8656ARMZ and the AD8651ARMZ share similar amplifier specifications, but they are not pin-compatible. A PCB designed for the dual AD8656ARMZ cannot directly accept the single AD8651ARMZ without layout changes, so substitution requires design validation against the datasheets.
What are the typical applications for the AD8656ARMZ and AD8651ARMZ?
Both amplifiers are suited for precision instrumentation, low-noise signal conditioning, photodiode amplification, audio, and medical instrumentation, where low voltage noise, rail-to-rail input/output, and a 2.7 V to 5.5 V supply are required.