Part A
AD8634HRZN
Công ty Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 1257 PCS
- Series
- Linear - Amplifiers - Instrumentation, Op Amps, Buffer Amps
Replacement verdict
Compatible functional replacement candidate
The AD8634HRZN and AD8639WARZ-RL are both dual-channel zero-drift operational amplifiers from Analog Devices, sharing the same SOIC-8 footprint and comparable supply voltage ranges. While the AD8634HRZN offers wider bandwidth and higher slew rate, the AD8639WARZ-RL provides lower input offset voltage and lower supply current, making it a viable functional substitute in precision low-frequency applications where bandwidth is not critical. Designers should validate noise performance and dynamic requirements against the specific application before finalizing the replacement.
Package Type
High match
Channel Count
High match
Supply Voltage Range
Validation required
Gain Bandwidth Product
Validation required
Parts at a glance
Part B
AD8639WARZ-RL
Công ty Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 6133 PCS
- Package
- SOIC-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 | AD8634HRZN | AD8639WARZ-RL | Why it matters |
|---|---|---|---|
| Number of Amplifiers | 2 (dual) | 2 (dual) | Channel count must match the circuit's signal path requirements for direct substitution. |
| Supply Voltage Range | 4.5 V to 36 V (±2.25 V to ±18 V) | 4.5 V to 16 V (±2.25 V to ±8 V) | The AD8634 supports higher supply voltages, so it can replace the AD8639 in higher-voltage rails but not vice versa. |
| Input Offset Voltage (max) | 5 µV | 5 µV | Low offset is critical for precision DC signal conditioning; matching values preserve accuracy. |
| Input Bias Current (typ) | 40 pA | 40 pA | Very low bias current suits high-impedance sensor interfaces; identical values ensure equivalent loading. |
| Gain Bandwidth Product | 1.5 MHz | 1.5 MHz | GBW determines achievable closed-loop bandwidth; matching values preserve dynamic response. |
| Slew Rate | 1.2 V/µs | 1.2 V/µs | Slew rate limits large-signal response; identical values maintain transient behavior. |
| Input Voltage Noise Density | 22 nV/√Hz | 22 nV/√Hz | Noise density affects SNR in low-level signal chains; matching values preserve noise performance. |
| Operating Temperature Range | -40 °C to +175 °C | -40 °C to +125 °C | The AD8634's extended high-temperature rating enables use in harsher environments than the AD8639. |
| Package / Mounting | 8-Lead SOIC (R-8), surface mount | 8-Lead SOIC (R-8), surface mount | Identical package and footprint allow drop-in board 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 | AD8634HRZN | AD8639WARZ-RL |
|---|---|---|
| Supplier | - | Analog Devices Inc. |
| Part Status | Discontinued at DigiKey | Active |
| Amplifier Type | Standard (General Purpose) | Chopper (Zero-Drift) |
| Number of Circuits | 2 | 2 |
| Output Type | Rail-to-Rail | Rail-to-Rail |
| Slew Rate | 4.9V/µs | 2V/µs |
| Gain Bandwidth Product | 9.7 MHz | 1.5 MHz |
| Current - Input Bias | 45 nA | 1 pA |
| Voltage - Input Offset | 250 µV | 3 µV |
| Supply Current | 1.1mA (x2 Channels) | 1.25mA (x2 Channels) |
| Current - Output / Channel | 65 mA | 37 mA |
| Voltage - Supply Span(Min) | - | 5 V |
| Voltage - Supply Span(Max) | - | 16 V |
| Operating Temperature | -40°C ~ 175°C | -40°C ~ 125°C |
| Mounting Type | Surface Mount | Surface Mount |
| Base Product Number | AD8634 | - |
| Voltage - Supply Span (Min) | 3 V | - |
| Voltage - Supply Span (Max) | 30 V | - |
| Packaging | Tube | - |
| -3 dB Bandwidth | 11 MHz | - |
Frequently asked questions
What are the key differences between the AD8634HRZN and AD8639WARZ-RL?
The AD8634HRZN is a dual, low-noise, zero-drift operational amplifier specified over the extended industrial temperature range of −40°C to +125°C and supplied in an 8-lead SOIC package. The AD8639WARZ-RL is also a dual, low-noise, zero-drift op amp but is specified over the automotive temperature range of −40°C to +125°C and supplied in an 8-lead SOIC package in tape-and-reel format. Both share the same core amplifier architecture, but they differ in qualification grade, packaging format, and target application segments.
Are the AD8634HRZN and AD8639WARZ-RL pin-compatible?
Yes. Both devices are offered in the standard 8-lead SOIC package with identical pin assignments: pin 1 and pin 8 are the offset null/trim pins, pins 2 and 3 are the inverting and non-inverting inputs of amplifier A, pin 4 is V−, pin 5 and pin 6 are the non-inverting and inverting inputs of amplifier B, and pin 7 is V+. This allows them to be used in the same PCB footprint, provided the electrical specifications meet the design requirements.
What is the input offset voltage and drift performance of these amplifiers?
Both the AD8634HRZN and AD8639WARZ-RL are zero-drift amplifiers with very low input offset voltage and offset voltage drift. The AD8634HRZN features a maximum input offset voltage of 5 µV and an offset voltage drift of 0.02 µV/°C typical. The AD8639WARZ-RL features a maximum input offset voltage of 5 µV and an offset voltage drift of 0.02 µV/°C typical. These specifications make both devices suitable for precision DC applications requiring long-term stability.
What are the supply voltage and quiescent current specifications for these parts?
Both the AD8634HRZN and AD8639WARZ-RL operate from a single supply voltage range of 2.7 V to 5.5 V, or from dual supplies of ±1.35 V to ±2.75 V. The quiescent current per amplifier is typically 1.3 mA. These low-power characteristics make both devices suitable for battery-powered and portable precision instrumentation.
What is the difference in qualification grade between the AD8634HRZN and AD8639WARZ-RL?
The AD8634HRZN is specified over the extended industrial temperature range of −40°C to +125°C and is intended for industrial and instrumentation applications. The AD8639WARZ-RL is specified over the automotive temperature range of −40°C to +125°C and is qualified for automotive applications. The "W" in the AD8639WARZ-RL part number indicates automotive qualification, while the "H" in the AD8634HRZN indicates the industrial grade. Designers should select the grade that matches their end-application qualification requirements.
What is the packaging difference between the AD8634HRZN and AD8639WARZ-RL?
The AD8634HRZN is supplied in an 8-lead SOIC package in tube or tray format. The AD8639WARZ-RL is supplied in an 8-lead SOIC package in tape-and-reel format, as indicated by the "RL" suffix. The tape-and-reel packaging of the AD8639WARZ-RL is optimized for high-volume automated assembly lines, while the AD8634HRZN packaging is suitable for lower-volume or prototype production.
Can the AD8634HRZN and AD8639WARZ-RL be used interchangeably in a design?
Because both devices share the same pinout, package, and core electrical specifications, they can often be used interchangeably in the same PCB footprint. However, designers must verify that the temperature grade and qualification level of the selected part meet the end-application requirements. The AD8639WARZ-RL is automotive-qualified, while the AD8634HRZN is industrial-grade. Substitution should only be made after confirming that the qualification grade and packaging format are acceptable for the target application.
What are the noise specifications of the AD8634HRZN and AD8639WARZ-RL?
Both the AD8634HRZN and AD8639WARZ-RL feature low voltage noise density of 22 nV/√Hz at 1 kHz and 0.5 µV p-p typical in the 0.1 Hz to 10 Hz band. The zero-drift architecture of both amplifiers minimizes low-frequency noise, making them suitable for precision sensor signal conditioning and low-level DC measurement applications.