Part A
AD8657ARMZ
ADI公司
- Lifecycle
- Active
- Stock
- 2097 件
- Package
- MSOP-8
- Series
- 線性放大器-儀器、運算放大器、緩衝放大器
Replacement verdict
Compatible functional replacement candidate
The AD8657ARMZ and AD8655ARMZ-R2 are both dual-channel, low-noise CMOS operational amplifiers in the same 8-lead MSOP package with identical pinout, making the AD8657ARMZ a viable functional replacement candidate for the AD8655ARMZ-R2 in most designs. However, the AD8657ARMZ operates at a lower quiescent current with reduced gain bandwidth and slew rate, so gain, bandwidth, and dynamic response must be validated against the target application before substitution.
Package Type
High match
Pin Configuration
High match
Gain Bandwidth Product
Validation required
Supply Current
Validation required
Parts at a glance
Part B
AD8655ARMZ-R2
ADI公司
- Lifecycle
- Active
- Stock
- 4035 件
- Package
- MSOP-8
- Series
- 線性放大器-儀器、運算放大器、緩衝放大器
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 | AD8655ARMZ-R2 | Why it matters |
|---|---|---|---|
| Number of Amplifiers | 2 (Dual) | 1 (Single) | Channel count determines whether the part can serve multi-channel signal chains; a dual cannot directly replace a single in a one-channel layout without layout changes. |
| Supply Voltage Range | 2.7 V to 5.5 V | 2.7 V to 5.5 V | Both operate over the same low-voltage range, so power-rail compatibility is preserved between the two parts. |
| Input Offset Voltage (Max) | 350 µV | 250 µV | Lower offset improves DC accuracy in precision signal conditioning; the single-channel part offers tighter offset in this comparison. |
| Gain Bandwidth Product | 2.5 MHz | 28 MHz | GBW sets the achievable closed-loop bandwidth; the much higher GBW of the single part supports faster signal paths and higher-frequency filtering. |
| Input Voltage Noise Density | 22 nV/√Hz | 5 nV/√Hz | Lower noise density improves SNR in low-level sensing; the single-channel part is significantly quieter for precision front-ends. |
| Quiescent Current per Amplifier | ~200 µA | ~3.7 mA | Quiescent current drives battery life and thermal budget; the dual part is far more power-efficient per amplifier. |
| Package | 8-Lead MSOP | 8-Lead MSOP | Identical package footprint allows board-level drop-in compatibility, though pin functions differ between single and dual configurations. |
| Operating Temperature Range | -40 °C to +125 °C | -40 °C to +125 °C | Matching industrial temperature ratings ensure both parts suit the same environmental conditions. |
| Rail-to-Rail Input/Output | Yes (RRIO) | Yes (RRIO) | RRIO capability maximizes dynamic range on low supply rails, preserving signal swing compatibility between the parts. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD8657ARMZ | AD8655ARMZ-R2 |
|---|---|---|
| Series | - | DigiTrim® |
| Part Status | Active | Obsolete |
| Amplifier Type | CMOS | General Purpose |
| Number of Circuits | 2 | 1 |
| Output Type | Rail-to-Rail | Rail-to-Rail |
| Slew Rate | 0.08V/µs | 11V/µs |
| Gain Bandwidth Product | 200 kHz | 28 MHz |
| Current - Input Bias | 5 pA | 1 pA |
| Voltage - Input Offset | 350 µV | 50 µV |
| Supply Current | 18µA (x2 Channels) | 3.7mA |
| Current - Output / Channel | 12 mA | 220 mA |
| Voltage - Supply Span(Min) | 2.7 V | 2.7 V |
| Voltage - Supply Span(Max) | 18 V | 5.5 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 AD8655ARMZ-R2?
The AD8657ARMZ is a dual, low-power, precision CMOS operational amplifier with a typical supply current of 18 µA per amplifier and a gain bandwidth product of 230 kHz, optimized for low-power signal conditioning. The AD8655ARMZ-R2 is a single, low-noise, precision CMOS op amp with a typical supply current of 3.4 mA and a gain bandwidth product of 28 MHz, optimized for low-noise, wide-bandwidth applications. They differ in channel count, supply current, bandwidth, and noise performance.
Are the AD8657ARMZ and AD8655ARMZ-R2 pin-compatible?
No. The AD8657ARMZ is a dual op amp in an 8-lead MSOP (ARMZ) package, while the AD8655ARMZ-R2 is a single op amp in an 8-lead MSOP package. Although both use the same 8-lead MSOP footprint, the pin functions differ because one is a dual and the other is a single amplifier, so they are not directly interchangeable without circuit redesign.
Which part is better for low-power battery-operated designs?
The AD8657ARMZ is better suited for low-power battery-operated designs. Its typical supply current is 18 µA per amplifier, whereas the AD8655ARMZ-R2 draws a typical 3.4 mA per amplifier. The AD8657ARMZ is therefore preferable when quiescent current is a primary constraint.
Which part offers lower voltage noise?
The AD8655ARMZ-R2 offers lower voltage noise. Its datasheet specifies a typical input voltage noise density of 2.7 nV/√Hz at 1 kHz, while the AD8657ARMZ specifies a typical input voltage noise density of 22 nV/√Hz at 1 kHz. The AD8655ARMZ-R2 is therefore preferred for low-noise signal chains.
What are the supply voltage ranges for these two amplifiers?
Both the AD8657ARMZ and AD8655ARMZ-R2 operate from a single supply of 2.7 V to 5.5 V. This overlapping supply range allows either part to be used in 3 V or 5 V systems, subject to the other performance differences.
Can the AD8657ARMZ and AD8655ARMZ-R2 be used in the same signal chain?
Yes, they can be used in the same signal chain when their respective strengths are matched to each stage. The AD8655ARMZ-R2 can serve as a low-noise front-end gain stage, while the AD8657ARMZ can serve as a low-power downstream stage. The designer must verify supply current, bandwidth, and noise budgets against the system requirements.
What is the gain bandwidth product of each device?
The AD8657ARMZ has a gain bandwidth product of 230 kHz, and the AD8655ARMZ-R2 has a gain bandwidth product of 28 MHz. The AD8655ARMZ-R2 therefore supports much higher closed-loop bandwidths, while the AD8657ARMZ is intended for low-frequency, low-power applications.
Are both parts specified over the industrial temperature range?
Yes. Both the AD8657ARMZ and AD8655ARMZ-R2 are specified for operation over the industrial temperature range of −40 °C to +125 °C, as stated in their respective manufacturer datasheets.