Part A
AD8561AR
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 4375 PCS
- Package
- SOIC-8
- Series
- Linear - Comparators
Replacement verdict
Not a drop-in replacement
The AD8564ARZ-REEL7 and AD8561AR are not drop-in replacements for one another. The AD8564ARZ-REEL7 is a quad high-speed comparator, while the AD8561AR is a single high-speed comparator, so channel count, package footprint, and pinout differ fundamentally. Designers must verify supply voltage range, input common-mode range, output logic compatibility, and propagation delay against the target application before considering either part as a substitute.
Different channel count
Different package footprint
Different pinout
Different output configuration
Parts at a glance
Part B
AD8564ARZ-REEL7
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 3564 PCS
- Package
- SOIC-16
- Series
- Linear - Comparators
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD8564ARZ-REEL7 | AD8561AR | Why it matters |
|---|---|---|---|
| Number of Comparators | 4 | 1 | Determines how many independent comparison channels are available in a single package, directly affecting circuit density and channel count. |
| Propagation Delay | 7 ns (typ) | 9.8 ns (typ) | Sets the maximum speed at which the comparator can respond to input changes, critical for high-speed signal processing and timing accuracy. |
| Supply Voltage Range | ±4.5 V to ±5.5 V (dual) / 4.5 V to 5.5 V (single) | ±2.5 V to ±5.5 V (dual) / 2.5 V to 5.5 V (single) | Defines the operating voltage window; a wider range allows greater flexibility across different system power rails. |
| Input Offset Voltage | 3 mV (max) | 2.5 mV (max) | Affects comparison accuracy; lower offset voltage reduces threshold error and improves precision in sensitive detection circuits. |
| Input Bias Current | 4 µA (typ) | 3 µA (typ) | Influences input impedance loading and error in high-impedance source applications; lower bias current is generally preferred. |
| Output Type | CMOS/TTL compatible push-pull | TTL/CMOS compatible | Determines how the comparator output interfaces with downstream logic; output drive style affects compatibility and need for pull-ups. |
| Package / Mounting | 14-Lead SOIC (surface mount, tape and reel) | 8-Lead SOIC (surface mount) | Package footprint and pin count affect PCB layout, board space, and whether a direct drop-in replacement is possible. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Indicates the environmental range over which specified performance is guaranteed, important for industrial and automotive applications. |
| Supply Current per Comparator | ~5.5 mA (typ, total) | ~6 mA (typ) | Impacts power budget and thermal design; lower current draw is beneficial for power-sensitive and battery-operated systems. |
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 | AD8561AR | AD8564ARZ-REEL7 |
|---|---|---|
| Part Status | Obsolete | Active |
| Type | General Purpose | General Purpose |
| Number of Elements | 1 | 4 |
| Output Type | CMOS, Complementary, TTL | CMOS, TTL |
| Voltage - Supply, Single/Dual (±) | 3V ~ 10V, ±1.5V ~ 5V | - |
| Voltage - Input Offset (Max) | 7mV @ 5V | 7mV @ 5V |
| Current - Input Bias(Max) | 6µA @ 5V | 4µA @ 5V |
| Current - Quiescent (Max) | 6mA, 3.3mA, 5.5mA | 14mA, 14mA, 7mA |
| CMRRPSRR(Typ) | 85dB CMRR, 65dB PSRR | 85dB CMRR, 80dB PSRR |
| Propagation Delay(Max) | 9.8ns | 9.8ns |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the primary differences between the AD8564ARZ-REEL7 and the AD8561AR?
The AD8564ARZ-REEL7 is a quad, 16-pin SOIC comparator supplied in tape-and-reel packaging, while the AD8561AR is a single, 8-pin SOIC comparator supplied in tube packaging. The AD8564 integrates four independent comparators in one package, whereas the AD8561 contains one comparator. Both are fast voltage comparators from Analog Devices, but they differ in channel count, package pinout, and packaging format.
Are the AD8564ARZ-REEL7 and AD8561AR pin-compatible?
No. The AD8564ARZ-REEL7 uses a 16-lead SOIC package (quad comparator), and the AD8561AR uses an 8-lead SOIC package (single comparator). The pin counts, pin functions, and PCB land patterns differ, so they are not drop-in replacements for one another.
Can the AD8561AR be used as a substitute for one channel of the AD8564ARZ-REEL7?
Functionally, the AD8561AR provides a single comparator, so it could serve one channel of the quad AD8564ARZ-REEL7 in principle. However, substitution requires verifying supply voltage range, input common-mode range, output logic levels, propagation delay, and pinout against the respective Analog Devices datasheets. Package and pinout differences mean a board redesign or adapter would be required.
What is the difference in packaging between the AD8564ARZ-REEL7 and the AD8561AR?
The AD8564ARZ-REEL7 suffix "REEL7" indicates tape-and-reel packaging intended for automated high-volume assembly. The AD8561AR is typically supplied in tube/rail packaging. Both use SOIC surface-mount packages, but the AD8564ARZ-REEL7 is a 16-lead SOIC and the AD8561AR is an 8-lead SOIC.
Do both parts operate from the same supply voltage range?
Both the AD8564 and AD8561 are designed to operate from a single supply or dual supplies within their specified ranges as documented in the Analog Devices datasheets. Designers must confirm the exact specified supply range for each part in the official datasheet before assuming interchangeability, since the two devices are separate product families.
Which part is better suited for multi-channel comparator applications?
The AD8564ARZ-REEL7 is better suited for multi-channel applications because it integrates four independent comparators in a single 16-lead SOIC package, reducing board space and component count. The AD8561AR provides only a single comparator per package, so multi-channel designs would require multiple devices.
Are both the AD8564ARZ-REEL7 and AD8561AR RoHS compliant?
The "Z" suffix in AD8564ARZ-REEL7 denotes a RoHS-compliant package per Analog Devices nomenclature. For the AD8561AR, RoHS status depends on the specific ordering variant; designers should verify the exact orderable part number and its compliance status in the Analog Devices datasheet or product page before finalizing a design.