Part A
AD8400AR50
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 614 PCS
- Series
- Data Acquisition - Digital Potentiometers
Replacement verdict
Not a drop-in replacement
The AD8402ARZ100 and AD8400AR50 are not drop-in replacements for each other. The AD8402ARZ100 is a dual-channel digital potentiometer with 100 kΩ end-to-end resistance, while the AD8400AR50 is a single-channel device with 50 kΩ resistance. The differing channel count, resistance value, and package footprint prevent direct substitution without circuit redesign and validation.
Different channel count
Different resistance value
Different package footprint
Different pin configuration
Parts at a glance
Part B
AD8402ARZ100
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 1274 PCS
- Package
- SOIC-14
- Series
- Data Acquisition - Digital Potentiometers
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD8402ARZ100 | AD8400AR50 | Why it matters |
|---|---|---|---|
| Number of Potentiometers | 2 (dual channel) | 1 (single channel) | Determines how many independent resistance channels are available; a dual device cannot be directly substituted where two separate channels are required. |
| End-to-End Resistance | 100 kΩ | 50 kΩ | Sets the nominal resistance range of the digital potentiometer, directly affecting the achievable resistance and circuit gain/attenuation values. |
| Number of Positions (Taps) | 256 | 256 | Defines the wiper resolution; both offer 8-bit resolution, so resolution is equivalent despite other differences. |
| Digital Interface | SPI (3-wire serial) | SPI (3-wire serial) | Both use the same serial control interface, simplifying firmware reuse, though channel addressing differs. |
| Supply Voltage Range | 2.7 V to 5.5 V | 2.7 V to 5.5 V | Confirms both parts operate over the same single-supply range, allowing use in the same low-voltage systems. |
| Package | 8-lead SOIC | 8-lead SOIC | Identical package and pin count ease board-level replacement, though pin functions differ between single and dual versions. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Matching temperature ratings ensure both parts suit the same industrial-grade environments. |
| Wiper Resistance | ~50 Ω (typical) | ~50 Ω (typical) | Wiper resistance adds to the set resistance and affects accuracy at low tap settings; comparable values mean similar error behavior. |
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 | AD8400AR50 | AD8402ARZ100 |
|---|---|---|
| Part Status | Obsolete | Active |
| Base Product Number | AD8400 | - |
| Digi Key Programmable | Not Verified | - |
| Taper | Linear | Linear |
| Configuration | Potentiometer | Potentiometer |
| Number of Circuits | 1 | 2 |
| Number of Taps | 256 | 256 |
| Resistance (Ohms) | 50k | - |
| Interface | SPI | SPI |
| Memory Type | Volatile | Volatile |
| Voltage - Supply | 2.7V ~ 5.5V | 2.7V ~ 5.5V |
| Tolerance | ±30% | ±30% |
| Temperature Coefficient (Typ) | 500ppm/°C | - |
| Mounting Type | Surface Mount | Surface Mount |
| Operating Temperature | -40°C ~ 125°C | -40°C ~ 125°C |
| Resistance - Wiper (Ohms) (Typ) | 200 | - |
| Packaging | Tube | - |
| Resistance(Ohms) | - | 100k |
| Temperature Coefficient(Typ) | - | 500ppm/°C |
Frequently asked questions
What are the key differences between the AD8402ARZ100 and the AD8400AR50?
The AD8402ARZ100 is a dual-channel, 100 kΩ digital potentiometer in a 14-lead SOIC package, while the AD8400AR50 is a single-channel, 50 kΩ digital potentiometer in an 8-lead SOIC package. The AD8402ARZ100 provides two independently programmable resistor channels, whereas the AD8400AR50 provides one channel. Both are 256-position devices from Analog Devices.
Are the AD8402ARZ100 and AD8400AR50 pin-compatible?
No. The AD8402ARZ100 uses a 14-lead SOIC package with two channels and separate terminal connections per channel, while the AD8400AR50 uses an 8-lead SOIC package with a single channel. The pin counts and pin functions differ, so they are not drop-in replacements for each other.
What is the end-to-end resistance of each device?
The AD8402ARZ100 has a nominal end-to-end resistance of 100 kΩ, and the AD8400AR50 has a nominal end-to-end resistance of 50 kΩ. Both offer 256 programmable positions (8-bit resolution) across the resistor string.
Do both devices use the same digital interface?
Yes. Both the AD8402ARZ100 and AD8400AR50 use a 3-wire SPI-compatible serial interface (CS, SDI, and CLK) for programming the wiper position. The AD8402ARZ100 requires additional address bits to select between its two channels, while the AD8400AR50 has only one channel to address.
What supply voltage range do these digital potentiometers support?
Both the AD8402ARZ100 and AD8400AR50 operate from a single supply of 2.7 V to 5.5 V, making them suitable for low-voltage digital control applications. The digital interface logic levels are referenced to the supply voltage.
Can the AD8400AR50 be used as a direct substitute for one channel of the AD8402ARZ100?
Functionally, one channel of the AD8402ARZ100 can be emulated by an AD8400AR50 only if the 50 kΩ versus 100 kΩ resistance difference is acceptable for the circuit. However, the AD8400AR50 is not a pin-for-pin replacement because the package and pinout differ, so the PCB layout must be redesigned.
What are the typical applications for these devices?
Both the AD8402ARZ100 and AD8400AR50 are used for digital volume control, programmable gain adjustment, offset and gain trimming, and adjustable reference levels. The dual-channel AD8402ARZ100 suits stereo or multi-channel trimming, while the single-channel AD8400AR50 suits compact single-path adjustment where board space is limited.