Part A
AD8400ARZ1
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 4740 Stückzahl
- Package
- SOIC-8
- Series
- Datenerfassung
Replacement verdict
Not a drop-in replacement
The AD8400ARZ1 and AD8402AR1 are both single-channel digital potentiometers from the AD840x family, but they differ in resolution, package, and interface configuration, so they are not interchangeable in a design without validation. The AD8400ARZ1 offers 1 kΩ end-to-end resistance in an 8-lead SOIC package, while the AD8402AR1 provides 1 kΩ resistance in a 14-lead SOIC package with a different internal architecture. Designers must verify footprint, resolution, and interface compatibility before considering substitution.
Different package footprint
Different resolution
Different interface configuration
Different channel architecture
Parts at a glance
Part B
AD8402AR1
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 2748 Stückzahl
- Package
- SOIC-14
- Series
- Datenerfassung
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 | AD8402AR1 | Why it matters |
|---|---|---|---|
| Number of Resistor Channels | 1 | 2 | Determines how many independent digital potentiometer channels are available; a single-channel part cannot replace a dual-channel part in circuits requiring two adjustable resistances. |
| End-to-End Resistance | 1 kΩ | 1 kΩ | Sets the nominal full-scale resistance range; matching values ensures the same adjustment span and current levels in the target circuit. |
| Resolution (Number of Positions) | 256 positions (8-bit) | 256 positions (8-bit) | Defines the step granularity of resistance adjustment; identical resolution preserves the same wiper step size and control precision. |
| Digital Interface | SPI (3-wire serial) | SPI (3-wire serial) | The communication protocol must match the host controller; both use the same serial interface, allowing firmware reuse. |
| Supply Voltage Range | 2.7 V to 5.5 V | 2.7 V to 5.5 V | Determines compatibility with the system power rail; identical ranges allow operation in the same voltage domain. |
| Package / Mounting | 8-lead SOIC (surface mount) | 14-lead SOIC (surface mount) | Footprint and pin count differ, so the PCB layout must accommodate the larger 14-lead package for the dual-channel device. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Confirms both parts are rated for the same industrial temperature environment, ensuring reliable operation under identical conditions. |
| Wiper Current Rating | 5 mA (typical max) | 5 mA (typical max) | Limits the load current the wiper can handle; matching ratings ensures the same drive capability for the connected load. |
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 | AD8400ARZ1 | AD8402AR1 |
|---|---|---|
| Supplier | - | Analog Devices Inc.,Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| Taper | Linear | Linear |
| Configuration | Potentiometer | Potentiometer |
| Number of Circuits | 1 | 2 |
| Number of Taps | 256 | 256 |
| Resistance(Ohms) | 1k | 1k |
| Interface | SPI | SPI |
| Memory Type | Volatile | Volatile |
| Voltage - Supply | 2.7V ~ 5.5V | 2.7V ~ 5.5V |
| Tolerance | ±33% | ±33% |
| Temperature Coefficient(Typ) | 700ppm/°C | 500ppm/°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 AD8402AR1 digital potentiometers?
The AD8400ARZ1 is a single-channel, 1 kΩ digital potentiometer in an 8-lead SOIC package, while the AD8402AR1 is a dual-channel, 1 kΩ digital potentiometer in a 14-lead SOIC package. Both are 256-position devices from Analog Devices with an SPI-compatible serial interface, but they differ in channel count and package pin count.
Are the AD8400ARZ1 and AD8402AR1 pin-compatible?
No. The AD8400ARZ1 uses an 8-lead SOIC package, whereas the AD8402AR1 uses a 14-lead SOIC package. The different pin counts and pinouts mean they are not drop-in replacements for each other and require different PCB footprints.
What is the end-to-end resistance of both devices?
Both the AD8400ARZ1 and AD8402AR1 are the 1 kΩ resistance option in the AD8400/AD8402 family, offering 256 programmable positions (8-bit resolution) across the end-to-end resistance.
Do both parts use the same digital interface?
Yes. Both the AD8400ARZ1 and AD8402AR1 use a 3-wire SPI-compatible serial interface (SDI, SDO, and CLK) with a chip select input, allowing daisy-chaining and microcontroller control. The AD8402AR1 provides independent control of two channels through the same interface.
What supply voltage range do the AD8400ARZ1 and AD8402AR1 support?
Both devices operate from a single supply of 2.7 V to 5.5 V, making them suitable for low-voltage digital control applications. They also feature a power-on reset that sets the wiper to midscale.
When should I choose the AD8402AR1 over the AD8400ARZ1?
Choose the AD8402AR1 when your design requires two independently programmable resistance channels in a single package, such as dual gain control or stereo level adjustment. Choose the AD8400ARZ1 when only one channel is needed and board space is limited, since it occupies a smaller 8-lead SOIC footprint.
Are both devices available in the same operating temperature range?
Yes. Both the AD8400ARZ1 and AD8402AR1 are specified for the industrial temperature range of −40 °C to +85 °C, as documented in the Analog Devices AD8400/AD8402/AD8403 datasheet.