Part A
AD8402ARZ100
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 1274 PCS
- Package
- SOIC-14
- Series
- Acquisição de dados - Potenciômetros Digitais
Replacement verdict
Not a drop-in replacement
The AD8400ARZ1 and AD8402ARZ100 are not drop-in replacements for one another. Although both are single-supply digital potentiometers from the same AD840x family, they differ in channel count, end-to-end resistance, and package configuration, so a direct board-level substitution is not possible without design changes.
Different channel count
Different end-to-end resistance
Different package type
Different pin configuration
Parts at a glance
Part B
AD8400ARZ1
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 4740 PCS
- Package
- SOIC-8
- Series
- Acquisição de dados - Potenciômetros Digitais
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD8400ARZ1 | AD8402ARZ100 | Why it matters |
|---|---|---|---|
| Number of Resistor Channels | 1 | 2 | Determines how many independent programmable resistance paths are available; a single-channel part cannot replace a dual-channel part in circuits needing two independent adjustments. |
| Nominal Resistance | 1 kΩ | 100 kΩ | Sets the end-to-end resistance range of the digital potentiometer; a 100x difference drastically changes the current/voltage scaling and cannot be substituted without redesigning surrounding circuitry. |
| Resolution (Number of Positions) | 256 positions (8-bit) | 256 positions (8-bit) | Defines the number of discrete wiper steps; matching 8-bit resolution means both offer the same adjustment granularity. |
| Digital Interface | SPI (3-wire serial) | SPI (3-wire serial) | The control bus must match the host microcontroller; identical SPI interfaces allow the same firmware protocol to drive either device. |
| Supply Voltage Range | 2.7 V to 5.5 V | 2.7 V to 5.5 V | Both operate over the same single-supply range, so power-rail compatibility is preserved between the two parts. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Identical industrial temperature ratings mean both are suitable for the same environmental conditions. |
| Package | 8-lead SOIC | 8-lead SOIC | Same package and footprint allow either part to be placed on the same PCB land pattern, though pin functions differ. |
| Wiper Resistance | ~50 Ω (typical) | ~50 Ω (typical) | Wiper resistance adds a fixed series term to the programmed resistance; similar values keep the effective resistance error comparable, though the nominal resistance difference dominates overall behavior. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD8402ARZ100 | AD8400ARZ1 |
|---|---|---|
| Part Status | Active | Active |
| Taper | Linear | Linear |
| Configuration | Potentiometer | Potentiometer |
| Number of Circuits | 2 | 1 |
| Number of Taps | 256 | 256 |
| Resistance(Ohms) | 100k | 1k |
| Interface | SPI | SPI |
| Memory Type | Volatile | Volatile |
| Voltage - Supply | 2.7V ~ 5.5V | 2.7V ~ 5.5V |
| Tolerance | ±30% | ±33% |
| Temperature Coefficient(Typ) | 500ppm/°C | 700ppm/°C |
| Mounting Type | Surface Mount | Surface Mount |
| Operating Temperature | -40°C ~ 125°C | -40°C ~ 125°C |
Frequently asked questions
What are the key differences between the AD8400ARZ1 and AD8402ARZ100?
The AD8400ARZ1 is a single-channel digital potentiometer with a 1 kΩ end-to-end resistance, while the AD8402ARZ100 is a dual-channel digital potentiometer with a 100 kΩ end-to-end resistance. Both are 8-bit devices in 8-lead SOIC packages, but they differ in channel count and resistance value.
Are the AD8400ARZ1 and AD8402ARZ100 pin-compatible?
No. The AD8400ARZ1 is a single-channel device in an 8-lead SOIC package, whereas the AD8402ARZ100 is a dual-channel device also in an 8-lead SOIC package but with a different pin function assignment to accommodate two potentiometers. They are not direct drop-in replacements for each other.
What is the resolution of both devices?
Both the AD8400ARZ1 and AD8402ARZ100 are 8-bit digital potentiometers, providing 256 wiper tap positions per channel.
What supply voltage range do the AD8400ARZ1 and AD8402ARZ100 support?
Both devices operate from a single supply voltage of 2.7 V to 5.5 V, making them suitable for low-voltage digital control applications.
How do the end-to-end resistance values compare between the two parts?
The AD8400ARZ1 offers a 1 kΩ end-to-end resistance, while the AD8402ARZ100 offers a 100 kΩ end-to-end resistance. The choice depends on the required current and impedance matching in the target circuit.
What digital interface do these digital potentiometers use?
Both the AD8400ARZ1 and AD8402ARZ100 use a 3-wire SPI-compatible serial interface for programming the wiper position.
Can the AD8402ARZ100 replace the AD8400ARZ1 in an existing design?
Not directly. Although both are 8-bit digital potentiometers in 8-lead SOIC packages, the AD8402ARZ100 has two channels and a 100 kΩ resistance versus the single channel and 1 kΩ resistance of the AD8400ARZ1. Pin assignments, channel count, and resistance value differ, so schematic and layout changes would be required.