Part A
AD8138ARZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 4208 PCS
- Package
- SOIC-8
- Series
- Linear - Amplifiers - Special Purpose
Replacement verdict
Compatible functional replacement candidate
The AD8138ARZ and AD8137YR are both differential ADC drivers from Analog Devices, but they are not drop-in interchangeable. The AD8138ARZ offers higher bandwidth and a fixed gain configuration, while the AD8137YR provides lower power consumption and externally adjustable gain. Designers must validate supply voltage, gain architecture, and thermal constraints before substituting one for the other in a given signal chain.
Bandwidth
Validation required
Gain Configuration
Validation required
Package Type
High match
Supply Voltage Range
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 | AD8138ARZ | AD8137YR | Why it matters |
|---|---|---|---|
| Amplifier Type | Differential ADC Driver | Differential ADC Driver | Both are differential drivers, but their internal architecture and target applications differ, affecting substitutability. |
| -3 dB Bandwidth | 320 MHz | 76 MHz | Bandwidth determines the maximum signal frequency the driver can handle; the AD8138 supports much higher-frequency signals. |
| Slew Rate | 1150 V/µs | 450 V/µs | Higher slew rate enables faster large-signal response and better performance with high-speed/high-amplitude signals. |
| Supply Voltage Range | 2.7 V to 11 V (±1.35 V to ±5.5 V) | 2.7 V to 12 V (±1.35 V to ±6 V) | The supply range determines compatibility with the system power rails; slight differences affect headroom and rail-to-rail operation. |
| Quiescent Supply Current | ~19 mA | ~3.2 mA | Lower quiescent current in the AD8137 makes it preferable for power-sensitive designs, while the AD8138 draws more for higher speed. |
| Input Voltage Noise | 5 nV/√Hz | 8.25 nV/√Hz | Lower input noise improves signal-to-noise ratio in precision and low-level signal applications. |
| Output Voltage Swing | Rail-to-rail output | Rail-to-rail output | Both offer rail-to-rail outputs, maximizing dynamic range within the available supply rails. |
| Package | 8-Lead SOIC | 8-Lead SOIC | Identical package and pinout allow potential drop-in replacement on the same PCB footprint. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +125 °C | The wider temperature range of the AD8137 suits harsher environments and industrial applications. |
Need help validating a replacement?
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD8138ARZ | AD8137YR |
|---|---|---|
| Supplier | - | Analog Devices Inc.,Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| Amplifier Type | - | Differential |
| Number of Circuits | - | 1 |
| Output Type | - | Differential, Rail-to-Rail |
| Slew Rate | - | 450V/µs |
| -3 dB Bandwidth | - | 110 MHz |
| Current - Input Bias | - | 500 nA |
| Voltage - Input Offset | - | 700 µV |
| Supply Current | - | 3.2mA |
| Current - Output / Channel | - | 20 mA |
| Voltage - Supply Span(Min) | - | 2.7 V |
| Voltage - Supply Span(Max) | - | 12 V |
| Operating Temperature | - | -40°C ~ 125°C |
| Mounting Type | Surface Mount | Surface Mount |
| Type | ADC Driver | - |
| Applications | Data Acquisition | - |
Frequently asked questions
What are the primary differences between the AD8138ARZ and AD8137YR?
The AD8138ARZ is a high-speed differential amplifier with a fixed gain of 1 (or 2 depending on configuration) and a -3 dB bandwidth of 320 MHz, housed in an 8-lead SOIC package. The AD8137YR is a lower-power, lower-cost differential amplifier with a -3 dB bandwidth of 100 MHz, housed in an 8-lead MSOP package. The AD8138ARZ is optimized for driving high-performance ADCs in applications requiring wide bandwidth, while the AD8137YR targets power-sensitive and cost-sensitive designs.
Are the AD8138ARZ and AD8137YR pin-compatible?
No. The AD8138ARZ uses an 8-lead SOIC (R-8) package, while the AD8137YR uses an 8-lead MSOP (RM-8) package. Although both are 8-lead packages, the physical dimensions and PCB land patterns differ, so they are not drop-in replacements without a board redesign.
Can the AD8137YR be used as a direct substitute for the AD8138ARZ in an existing design?
Not directly. Beyond the package difference (MSOP vs SOIC), the AD8137YR has a lower -3 dB bandwidth (100 MHz vs 320 MHz) and different supply current and noise characteristics. A substitution requires re-validating the signal chain, particularly ADC driving performance, settling time, and distortion at the target frequency.
How do the supply current and power consumption of the AD8138ARZ and AD8137YR compare?
The AD8138ARZ typically draws about 14 mA per amplifier from a ±5 V supply. The AD8137YR is a lower-power device, typically drawing about 3.6 mA per amplifier. The AD8137YR is therefore preferable in power-sensitive applications, while the AD8138ARZ offers higher bandwidth at the cost of higher supply current.
What are the typical applications for each device?
The AD8138ARZ is commonly used as a differential ADC driver in high-speed data acquisition, medical imaging, and communications systems where wide bandwidth and low distortion are critical. The AD8137YR is suited to portable instrumentation, low-power signal conditioning, and cost-sensitive differential signal chains where 100 MHz bandwidth is sufficient.
Do both devices support single-supply operation?
Yes. Both the AD8138ARZ and AD8137YR support single-supply and dual-supply operation. The AD8138ARZ operates from a single 3 V to 10 V supply or dual ±1.5 V to ±5 V supplies. The AD8137YR operates from a single 2.7 V to 12 V supply or dual ±1.35 V to ±6 V supplies. Designers should verify the output swing and common-mode range against the specific supply rails in their application.
Which device offers better distortion performance for ADC driving?
The AD8138ARZ generally provides lower harmonic distortion at higher frequencies due to its wider bandwidth and higher quiescent current. The AD8137YR offers adequate distortion performance for lower-frequency or lower-resolution ADC applications. The appropriate choice depends on the ADC resolution, sampling rate, and input frequency of the target design.