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 AD8657ARMZ and AD8656ARMZ are both dual-channel CMOS operational amplifiers from Analog Devices in the same 8-lead MSOP package, sharing identical pinout and supply voltage range, making them functionally interchangeable in most designs. The AD8657ARMZ offers lower quiescent current and wider operating temperature range, while the AD8656ARMZ provides higher unity-gain bandwidth and faster slew rate. Designers should validate dynamic performance requirements before substituting, but the shared package, pinout, and supply compatibility support a straightforward replacement path.
Package Type
High match
Pin Configuration
High match
Supply Voltage Range
High match
Gain Bandwidth Product
Validation required
Parts at a glance
Part B
AD8657ARMZ
Công ty Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 2097 PCS
- Package
- MSOP-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 | AD8657ARMZ | AD8656ARMZ | Why it matters |
|---|---|---|---|
| Number of Amplifiers | 2 | 2 | Both are dual op-amps, so channel count is compatible for direct substitution in dual-amplifier circuits. |
| Supply Voltage Range | 2.7 V to 5.5 V | 2.7 V to 5.5 V | Matching supply ranges ensure the replacement operates correctly in the same power rail configuration. |
| Input Offset Voltage (Max) | 250 µV | 250 µV | Offset voltage directly affects DC accuracy; identical limits mean comparable precision in signal chains. |
| Input Bias Current (Typ) | 0.5 pA | 0.5 pA | Very low bias current is critical for high-impedance sensor interfaces; matching values preserve input loading behavior. |
| Gain Bandwidth Product | 2.4 MHz | 28 MHz | GBW determines the maximum signal frequency the amplifier can handle; the large difference affects bandwidth-critical designs. |
| Slew Rate | 1.2 V/µs | 11 V/µs | Slew rate limits large-signal transient response; the AD8656 is significantly faster, affecting dynamic performance. |
| Input Voltage Noise Density | 22 nV/√Hz | 2.7 nV/√Hz | Lower noise density improves SNR in low-level signal applications; the AD8656 offers substantially better noise performance. |
| Quiescent Current per Amplifier (Typ) | 18 µA | 2.3 mA | Quiescent current drives power consumption; the AD8657 is far more power-efficient, which matters for battery-powered designs. |
| Operating Temperature Range | -40 °C to +125 °C | -40 °C to +125 °C | Identical temperature ratings ensure both parts meet the same environmental requirements. |
| Package | 8-Lead MSOP | 8-Lead MSOP | Same package and pinout allow drop-in PCB replacement without layout changes. |
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 | AD8657ARMZ |
|---|---|---|
| Series | DigiTrim® | - |
| Part Status | Active | Active |
| Amplifier Type | CMOS | CMOS |
| Number of Circuits | 2 | 2 |
| Output Type | Rail-to-Rail | Rail-to-Rail |
| Slew Rate | 11V/µs | 0.08V/µs |
| Gain Bandwidth Product | 28 MHz | 200 kHz |
| Current - Input Bias | 1 pA | 5 pA |
| Voltage - Input Offset | 50 µV | 350 µV |
| Supply Current | 3.7mA (x2 Channels) | 18µA (x2 Channels) |
| Current - Output / Channel | 220 mA | 12 mA |
| Voltage - Supply Span(Min) | 2.7 V | 2.7 V |
| Voltage - Supply Span(Max) | 5.5 V | 18 V |
| Operating Temperature | -40°C ~ 125°C | -40°C ~ 125°C |
| Mounting Type | Surface Mount | Surface Mount |
| -3 dB Bandwidth | - | 305 kHz |
Frequently asked questions
What are the key differences between the AD8657ARMZ and AD8656ARMZ operational amplifiers?
The AD8657ARMZ is a dual, low-power, precision CMOS operational amplifier with a typical supply current of 22 µA per amplifier and a gain bandwidth product of 230 kHz, optimized for low-power precision signal conditioning. The AD8656ARMZ is a dual, low-noise, precision CMOS operational amplifier with a typical supply current of 2.3 mA per amplifier and a gain bandwidth product of 28 MHz, optimized for low-noise, higher-bandwidth applications. Both are offered in 8-lead MSOP (RMZ) packages and operate on single supplies from 2.7 V to 5.5 V.
Are the AD8657ARMZ and AD8656ARMZ pin-compatible?
Yes. Both devices are dual operational amplifiers in the same 8-lead MSOP (RMZ) package and share the standard dual op-amp pinout (1: OUT A, 2: -IN A, 3: +IN A, 4: V-, 5: +IN B, 6: -IN B, 7: OUT B, 8: V+). This allows board-level interchangeability, but electrical differences must be validated for the target design.
Can the AD8657ARMZ be used as a direct drop-in replacement for the AD8656ARMZ?
Not unconditionally. Although the packages and pinouts match, the AD8657ARMZ has a much lower gain bandwidth product (230 kHz typical vs. 28 MHz typical) and lower quiescent current (22 µA vs. 2.3 mA per amplifier typical). Circuits designed for the AD8656ARMZ bandwidth, noise, or output drive may not meet specifications with the AD8657ARMZ, so the replacement must be validated against the application requirements.
How do the quiescent supply currents of the AD8657ARMZ and AD8656ARMZ compare?
The AD8657ARMZ is specified with a typical supply current of 22 µA per amplifier, making it suitable for battery-powered and low-power precision applications. The AD8656ARMZ is specified with a typical supply current of 2.3 mA per amplifier, reflecting its higher bandwidth and lower noise design. The AD8657ARMZ therefore offers roughly two orders of magnitude lower quiescent current.
How do the noise characteristics of the AD8657ARMZ and AD8656ARMZ compare?
The AD8656ARMZ is designed as a low-noise amplifier with a typical voltage noise density of 2.7 nV/√Hz at 1 kHz. The AD8657ARMZ is a low-power precision amplifier with correspondingly higher voltage noise density, typically around 60 nV/√Hz at 1 kHz. Designs requiring low noise should favor the AD8656ARMZ, while low-power precision designs may favor the AD8657ARMZ.
What supply voltage range do the AD8657ARMZ and AD8656ARMZ support?
Both the AD8657ARMZ and AD8656ARMZ operate from a single supply voltage range of 2.7 V to 5.5 V, and both are specified for operation over the extended industrial temperature range of -40 °C to +125 °C. This common supply and temperature range simplifies comparison and substitution evaluation between the two devices.
Which device is better suited for low-power precision signal conditioning?
The AD8657ARMZ is better suited for low-power precision signal conditioning due to its typical 22 µA per amplifier supply current and precision CMOS input characteristics, making it appropriate for portable and battery-operated instrumentation. The AD8656ARMZ, with its 2.3 mA per amplifier supply current and 28 MHz gain bandwidth, is better suited for low-noise, higher-bandwidth signal chains where power consumption is less critical.
Do the AD8657ARMZ and AD8656ARMZ share the same package and temperature grade?
Yes. Both devices are available in the 8-lead MSOP package designated by the RMZ suffix and are specified over the -40 °C to +125 °C industrial temperature range. The shared package and temperature grade mean the primary selection criteria between them are electrical performance parameters such as bandwidth, noise, and quiescent current.