AD8479ARZ Equivalent & Substitute Parts

Part Overview

The AD8479ARZ is a general-purpose operational amplifier manufactured by Analog Devices Inc., designed for rail-to-rail output applications in low-frequency signal conditioning and amplification circuits. This device operates across a wide supply voltage range of 5V to 36V and is housed in an 8-SOIC surface-mount package. The part is currently in Active product status with 1746 units available in inventory.

Substitute parts become necessary when the AD8479ARZ reaches end-of-life status, when supply constraints occur, or when application requirements demand alternative performance characteristics such as higher bandwidth, lower input offset voltage, or different supply voltage specifications.

Substiute Parts

AD8479ARZ

Analog Devices Inc.In Stock: 1845AD8479ARZ Datasheet

Current PartRFQ

OPA656UB

Texas InstrumentsIn Stock: 1935OPA656UB Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution compatibility for the AD8479ARZ is determined by the following critical parameters:

Package Compatibility: The substitute part must use the 8-SOIC surface-mount package to ensure direct PCB footprint compatibility without layout modifications.

Supply Voltage Range: The substitute must operate within or encompass the 5V to 36V supply voltage specification of the AD8479ARZ. Parts with narrower supply ranges may not function in all intended applications.

Output Configuration: Rail-to-rail output capability is a defining characteristic of the AD8479ARZ. Substitute parts must maintain this output swing specification to preserve signal fidelity in single-supply or low-voltage applications.

Number of Circuits: The AD8479ARZ contains a single amplifier circuit. Substitute parts must also contain exactly one circuit to maintain pin compatibility and functional equivalence.

Electrical Performance: While the AD8479ARZ operates at 8V/µs slew rate and 130 kHz bandwidth, substitute parts may exceed these specifications without creating functional incompatibility, provided all other parameters align.

Compliance and Status: All substitute parts must maintain ROHS3 compliance and appropriate moisture sensitivity ratings for manufacturing and storage requirements.

The OPA656UB from Texas Instruments is identified as a substitute part. However, this part operates under different electrical specifications and supply voltage constraints that require engineering evaluation for specific applications.

Parameter Comparison

Engineering Selection Recommendations

AD8479ARZ (Primary Selection): This part maintains Active product status with established supply availability (1746 units in stock). It is ROHS3 compliant and suitable for applications requiring wide supply voltage operation (5V to 36V) with extended operating temperature range (-40°C to 125°C). Selection of the AD8479ARZ is appropriate for new designs and long-term production requirements.

OPA656UB (Conditional Substitute): This part carries Last Time Buy status, indicating limited future availability. The OPA656UB is ROHS3 compliant and shares the 8-SOIC package footprint with the AD8479ARZ. However, critical differences exist:

The OPA656UB operates with a restricted supply voltage range (8V to 12V minimum and maximum), which does not encompass the full 5V to 36V range of the AD8479ARZ. Applications requiring operation below 8V or above 12V cannot use this substitute.

The OPA656UB exhibits significantly higher slew rate (295V/µs versus 8V/µs) and bandwidth (500 MHz versus 130 kHz), characteristics that may introduce stability concerns in circuits designed for the lower-bandwidth AD8479ARZ without circuit redesign.

The OPA656UB operates to a maximum temperature of 85°C, compared to 125°C for the AD8479ARZ, restricting use in high-temperature environments.

Selection of the OPA656UB is limited to applications where supply voltage remains within 8V to 12V, operating temperature does not exceed 85°C, and the higher bandwidth does not create circuit instability.

Frequently Asked Questions (FAQ)

Q: Can the OPA656UB directly replace the AD8479ARZ in all applications?

A: No. The OPA656UB has a restricted supply voltage range (8V to 12V) compared to the AD8479ARZ (5V to 36V). Applications operating outside this range cannot use the OPA656UB. Additionally, the OPA656UB has a lower maximum operating temperature (85°C versus 125°C).

Q: Are the package footprints identical between AD8479ARZ and OPA656UB?

A: Yes. Both parts use the 8-SOIC package with 0.154" width (3.90mm). PCB footprints are mechanically compatible without layout modification.

Q: What is the significance of the OPA656UB's Last Time Buy status?

A: Last Time Buy status indicates that Texas Instruments has announced end-of-life for this product. Future availability is limited, and inventory will eventually be depleted. New designs should not select parts with Last Time Buy status.

Q: Why does the OPA656UB have higher slew rate and bandwidth than the AD8479ARZ?

A: The OPA656UB is classified as a voltage feedback amplifier optimized for higher-frequency applications, while the AD8479ARZ is a general-purpose amplifier designed for lower-frequency signal conditioning. These are fundamentally different device architectures with different performance targets.

Q: Can I use the OPA656UB in a circuit designed for the AD8479ARZ if I operate it within 8V to 12V?

A: Mechanical and electrical compatibility exist within the specified supply voltage range. However, the significantly higher bandwidth and slew rate of the OPA656UB may cause circuit instability, oscillation, or unexpected frequency response if the original circuit was designed without compensation for these characteristics. Circuit analysis and testing are required for each specific application.

Q: What compliance certifications apply to both parts?

A: Both the AD8479ARZ and OPA656UB are ROHS3 compliant, REACH unaffected, and classified under ECCN EAR99. Both carry Moisture Sensitivity Level 3 (168 Hours). These certifications ensure compatibility with modern manufacturing and environmental regulations.

Q: Is the AD8479ARZ suitable for new product designs?

A: Yes. The AD8479ARZ maintains Active product status with established supply availability. It is appropriate for new designs requiring general-purpose amplification with wide supply voltage operation and extended temperature range.