Part A
AD8629ARMZ
Компания Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 3786 ПКС
- Package
- TSSOP-8
- Series
- Линейные - Усилетели - Приборы, ОП Усилетели, Буферные Усилетели
Replacement verdict
Compatible functional replacement candidate
The AD8629ARMZ and AD8627AKS-R2 are both precision, low-noise operational amplifiers from Analog Devices, but they differ in package, supply voltage range, and quiescent current. The AD8629ARMZ is a zero-drift, rail-to-rail input/output dual op amp in an MSOP-8 package, while the AD8627AKS-R2 is a single low-noise JFET-input op amp in an SC-70-5 package. Because the channel count, package footprint, and input bias current characteristics differ, the AD8627AKS-R2 is not a direct drop-in replacement for the AD8629ARMZ; however, for low-frequency, high-impedance signal-conditioning applications where a single amplifier suffices, it can serve as a functional substitute after validating supply voltage, gain bandwidth, and board layout constraints.
Channel Count
Validation required
Package Type
Not compatible
Input Bias Current
High match
Supply Voltage Range
Validation required
Parts at a glance
Part B
AD8627AKS-R2
Компания Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 7361 ПКС
- Package
- SC-70-5-5
- 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 | AD8629ARMZ | AD8627AKS-R2 | Why it matters |
|---|---|---|---|
| Number of Amplifiers | 2 (Dual) | 1 (Single) | Channel count determines whether the part can serve multi-channel signal paths; a dual cannot directly replace a single without layout changes. |
| Input Offset Voltage (Max) | 5 µV | 750 µV | Lower offset improves DC precision; the AD8629 is a zero-drift part suited to high-accuracy sensing, while the AD8627 has much larger offset. |
| Input Bias Current (Typ) | 30 pA | 1 pA | Bias current affects error in high-impedance sources; both are low, but the AD8627 offers slightly lower bias current. |
| Gain Bandwidth Product | 2.5 MHz | 5 MHz | GBW sets the achievable closed-loop bandwidth; the AD8627 supports roughly twice the bandwidth of the AD8629. |
| Slew Rate | 1 V/µs | 5 V/µs | Slew rate limits large-signal response speed; the AD8627 handles faster transients than the AD8629. |
| Supply Voltage Range | 2.7 V to 5 V (single) / ±1.35 V to ±2.5 V (dual) | 5 V to 26 V (single) / ±2.5 V to ±13 V (dual) | Operating supply range determines compatibility with the system rail; the AD8627 supports much higher supply voltages than the AD8629. |
| Supply Current per Amplifier (Typ) | 1.0 mA | 0.8 mA | Quiescent current impacts power budget; both are low-power, with the AD8627 drawing slightly less per amplifier. |
| Input Voltage Noise Density (1 kHz) | 22 nV/√Hz | 16 nV/√Hz | Noise density affects SNR in low-level signal chains; the AD8627 provides lower voltage noise at 1 kHz. |
| Package | 8-Lead MSOP | 5-Lead SC70 | Package footprint and pinout must match the PCB; these parts are not drop-in compatible due to different package types. |
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 | AD8629ARMZ | AD8627AKS-R2 |
|---|---|---|
| Supplier | - | Analog Devices Inc. |
| Part Status | Active | Obsolete |
| Amplifier Type | Zero-Drift | J-FET |
| Number of Circuits | 2 | 1 |
| Output Type | Rail-to-Rail | Rail-to-Rail |
| Slew Rate | 1V/µs | 5V/µs |
| Gain Bandwidth Product | 2.5 MHz | 5 MHz |
| Current - Input Bias | 30 pA | 0.25 pA |
| Voltage - Input Offset | 1 µV | 350 µV |
| Supply Current | - | 710µA |
| Current - Output / Channel | 30 mA | 15 mA |
| Voltage - Supply Span(Min) | 2.7 V | 5 V |
| Voltage - Supply Span(Max) | 5 V | 26 V |
| Operating Temperature | -40°C ~ 125°C | -40°C ~ 85°C |
| Mounting Type | Surface Mount | Surface Mount |
| -3 dB Bandwidth | 2.5 MHz | - |
Frequently asked questions
What are the primary differences between the AD8629ARMZ and the AD8627AKS-R2?
The AD8629ARMZ is a dual, zero-drift, rail-to-rail input/output operational amplifier supplied in an 8-lead MSOP (RM) package. The AD8627AKS-R2 is a single, low-power, precision JFET-input operational amplifier supplied in a 5-lead SC70 (KS) package and is provided on a 7-inch reel in 250-unit quantities (R2). The most significant differences are channel count (dual vs. single), input stage architecture (zero-drift CMOS vs. JFET), package footprint, and pin count.
Are the AD8629ARMZ and AD8627AKS-R2 pin-compatible or footprint-compatible?
No. The AD8629ARMZ uses an 8-lead MSOP package, while the AD8627AKS-R2 uses a 5-lead SC70 package. The two devices have different pin counts, pin functions, and PCB land patterns, so they cannot be interchanged on the same footprint without a board redesign.
How do the input bias current and input architecture of these two amplifiers compare?
The AD8629ARMZ uses a zero-drift CMOS input stage with very low input bias current, making it suitable for high-impedance and low-offset applications. The AD8627AKS-R2 uses a JFET input stage, which provides low input bias current and high input impedance but with different bias-current behavior over temperature than a zero-drift CMOS design. The appropriate choice depends on the offset and bias-current requirements of the target circuit.
Which device is better suited for low-offset, low-drift precision signal conditioning?
The AD8629ARMZ is the zero-drift amplifier in this comparison and is intended for applications requiring very low offset voltage and low offset drift over temperature and time. The AD8627AKS-R2 is a precision JFET-input amplifier but does not employ zero-drift architecture. For designs where offset drift is a dominant error source, the AD8629ARMZ is the more appropriate selection based on its zero-drift topology.
Can the AD8627AKS-R2 replace one channel of the AD8629ARMZ in an existing design?
Not as a direct drop-in replacement. Although both are operational amplifiers, they differ in package, pinout, channel count, and input architecture. Any substitution requires verifying supply voltage range, input common-mode range, output swing, gain bandwidth, offset, bias current, and package footprint against the manufacturer datasheets for the specific circuit.
What does the R2 suffix on the AD8627AKS-R2 indicate?
The R2 suffix denotes the packaging and shipping format specified by the manufacturer, indicating a tape-and-reel configuration in a defined quantity per reel. It does not change the electrical specifications of the AD8627AKS device itself; the electrical performance is determined by the base part number AD8627 and the KS (SC70) package.
How should the supply voltage and power requirements be evaluated when comparing these parts?
Both devices are operational amplifiers intended for low-power signal conditioning, but their specified supply voltage ranges, quiescent current, and output drive capability must be confirmed individually from the respective manufacturer datasheets. Because the AD8629ARMZ is a dual amplifier and the AD8627AKS-R2 is a single amplifier, total system supply current and channel count must be evaluated at the circuit level rather than by direct part-to-part comparison.
Which part should be selected for a single-channel, space-constrained precision design?
The AD8627AKS-R2 is the single-channel device in a 5-lead SC70 package, which is advantageous where only one amplifier channel is needed and board space is limited. The AD8629ARMZ provides two channels in an 8-lead MSOP package and would be selected when dual-channel signal conditioning is required. Selection should be based on channel count, package size, and the required input architecture verified from the datasheets.