Part A
AD8065ARZ
Công ty Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 6652 PCS
- Package
- SOIC-8
- Series
- Linear - Amplifiers - Instrumentation, OP Amps, Buffer Amps
Replacement verdict
Compatible functional replacement candidate
The AD8065ARZ and AD8061AR are both single-channel, voltage-feedback operational amplifiers in the same SOIC-8 package, making them a viable functional replacement candidate in many designs. However, the AD8065ARZ offers substantially higher bandwidth and a wider supply range, while the AD8061AR is optimized for lower supply voltage operation. Designers should validate gain-bandwidth requirements, supply voltage headroom, and input bias current tolerance before substituting one for the other in a given circuit.
Package Type
High match
Channel Count
High match
Supply Voltage Range
Validation required
Gain Bandwidth Product
Validation required
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD8065ARZ | AD8061AR | Why it matters |
|---|---|---|---|
| Amplifier Type | Voltage Feedback | Voltage Feedback | Both are voltage-feedback op amps, so the basic feedback topology and design equations are the same. |
| Number of Circuits | 1 | 1 | Single-channel devices; channel count must match the board layout and signal chain requirements. |
| Gain Bandwidth Product | 145 MHz | 320 MHz | GBWP sets the achievable closed-loop bandwidth; the AD8061 offers roughly twice the small-signal bandwidth. |
| Slew Rate | 180 V/µs | 300 V/µs | Slew rate limits large-signal response and distortion at high frequencies; the AD8061 slews faster. |
| Input Offset Voltage (max) | 1.5 mV | 6 mV | Lower offset improves DC accuracy; the AD8065 is the more precise choice for precision DC applications. |
| Input Bias Current (typ) | 6 pA | 3.5 µA | Very low bias current (FET input) minimizes errors with high-impedance sources; the AD8061's bipolar input draws far more. |
| Supply Voltage Range | 5 V to 24 V (±2.5 V to ±12 V) | 2.7 V to 8 V | Operating supply range determines compatibility with the system rail; the AD8065 supports much higher supplies. |
| Quiescent Supply Current (typ) | 6.4 mA | 6.8 mA | Quiescent current affects power budget and thermal design; both are similar low-power class devices. |
| Input Voltage Noise Density | 7 nV/√Hz | 8.5 nV/√Hz | Lower voltage noise improves SNR in low-level signal paths; the AD8065 is slightly quieter. |
| Package / Mounting | 8-SOIC (surface mount) | 8-SOIC (surface mount) | Identical SOIC-8 footprint allows direct board-level drop-in substitution without layout changes. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD8065ARZ | AD8061AR |
|---|---|---|
| Supplier | - | Analog Devices Inc.,Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| Amplifier Type | Voltage Feedback | Voltage Feedback |
| Number of Circuits | 1 | 1 |
| Output Type | Rail-to-Rail | Rail-to-Rail |
| Slew Rate | 180V/µs | 650V/µs |
| -3 dB Bandwidth | 145 MHz | 320 MHz |
| Current - Input Bias | 3 pA | 3.5 µA |
| Voltage - Input Offset | 400 µV | 1 mV |
| Supply Current | 6.6mA | 6.8mA |
| Current - Output / Channel | 30 mA | 50 mA |
| Voltage - Supply Span(Min) | 5 V | 2.7 V |
| Voltage - Supply Span(Max) | 24 V | 8 V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Mounting Type | Surface Mount | Surface Mount |
| Series | FastFET™ | - |
Frequently asked questions
What are the primary differences between the AD8065ARZ and the AD8061AR?
The AD8065ARZ is a single, high-performance, voltage-feedback operational amplifier with FET inputs, offering a 145 MHz bandwidth and a 180 V/µs slew rate. The AD8061AR is a single, low-cost, voltage-feedback operational amplifier with a 300 MHz bandwidth and a 170 V/µs slew rate. The AD8065ARZ is optimized for low input bias current and low noise, while the AD8061AR is optimized for low cost and high speed.
Are the AD8065ARZ and AD8061AR pin-compatible?
Yes, both devices are offered in an 8-lead SOIC package and share the same standard operational amplifier pinout. However, pin compatibility does not guarantee functional equivalence; circuit performance must be validated when substituting one for the other.
Which device has lower input bias current, the AD8065ARZ or the AD8061AR?
The AD8065ARZ has a significantly lower input bias current of 6 pA typical, owing to its FET input stage. The AD8061AR has a bipolar input stage with an input bias current of 3.5 µA typical. The AD8065ARZ is therefore preferable for high-impedance sensor and photodiode applications.
How do the input voltage noise specifications compare between the AD8065ARZ and AD8061AR?
The AD8065ARZ specifies an input voltage noise density of 7 nV/√Hz at 10 kHz. The AD8061AR specifies an input voltage noise density of 8.5 nV/√Hz at 10 kHz. The AD8065ARZ provides slightly lower voltage noise, making it better suited for low-noise signal conditioning.
What are the supply voltage and quiescent current specifications for these two amplifiers?
Both the AD8065ARZ and AD8061AR operate from a single supply of 5 V to 24 V or a dual supply of ±2.5 V to ±12 V. The AD8065ARZ draws a typical quiescent current of 6.4 mA, while the AD8061AR draws a typical quiescent current of 8.5 mA.
Which amplifier is better suited for high-speed signal chains, the AD8065ARZ or the AD8061AR?
The AD8061AR offers a higher -3 dB bandwidth of 300 MHz compared to 145 MHz for the AD8065ARZ, and a faster settling time. For applications prioritizing raw speed and cost, the AD8061AR is advantageous; for applications requiring low noise and low input bias current at moderate speed, the AD8065ARZ is preferable.
Can the AD8061AR be used as a direct drop-in replacement for the AD8065ARZ in an existing design?
While the packages and pinouts are compatible, a direct drop-in replacement is not recommended without evaluation. Differences in input bias current, noise, quiescent current, and bandwidth can affect circuit behavior. The replacement should be validated against the specific application requirements using the respective manufacturer datasheets.