Part A
AD8400AR50
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 614 PCS
- Series
- Acquisição de dados - Potenciômetros Digitais
Replacement verdict
Not a drop-in replacement
The AD8400ARZ1 and AD8400AR50 are both single-channel digital potentiometers in the same SOIC-8 package, but they differ fundamentally in end-to-end resistance (1 kΩ versus 50 kΩ), which directly changes wiper resistance behavior, power dissipation, and circuit tuning range. Because the resistance value is a core functional parameter that cannot be compensated without redesigning the surrounding analog network, the AD8400AR50 is not a drop-in substitute for the AD8400ARZ1.
Different end-to-end resistance
Different wiper resistance ratio
Different power dissipation
Circuit retuning required
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 | AD8400AR50 | Why it matters |
|---|---|---|---|
| End-to-End Resistance | 1 kΩ | 50 kΩ | The nominal resistance directly sets the digital potentiometer's wiper resistance range and the current/voltage scaling in the circuit; a 1 kΩ vs 50 kΩ part is not functionally interchangeable without redesigning surrounding circuitry. |
| Number of Positions (Taps) | 256 | 256 | Tap count determines the resolution of wiper adjustment; identical resolution means the same control granularity is available in both parts. |
| Interface Type | SPI (3-wire serial) | SPI (3-wire serial) | The digital control interface must match the host controller; both use the same serial protocol, so firmware and bus wiring are compatible. |
| Number of Potentiometers | 1 | 1 | Channel count determines how many independent resistance settings are available; both are single-channel devices. |
| Supply Voltage Range | 2.7 V to 5.5 V | 2.7 V to 5.5 V | The operating supply range must cover the system rail; identical ranges mean both can be powered from the same 3 V or 5 V supply. |
| Package / Mounting | 8-Lead SOIC (surface mount) | 8-Lead SOIC (surface mount) | Package and footprint must match the PCB layout for a drop-in replacement; both share the same 8-lead SOIC footprint. |
| Wiper Resistance | Approximately 50 Ω (typical, at 1 kΩ end-to-end) | Approximately 50 Ω (typical, at 50 kΩ end-to-end) | Wiper resistance adds a fixed series error to the programmed resistance; while the typical value is similar, its relative impact is far larger on the 1 kΩ part, affecting accuracy and minimum achievable resistance. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | The temperature range must cover the application environment; identical ratings mean both suit the same industrial-grade operating conditions. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD8400AR50 | AD8400ARZ1 |
|---|---|---|
| Part Status | Obsolete | Active |
| Base Product Number | AD8400 | - |
| Digi Key Programmable | Not Verified | - |
| Taper | Linear | Linear |
| Configuration | Potentiometer | Potentiometer |
| Number of Circuits | 1 | 1 |
| 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% | ±33% |
| 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) | - | 1k |
| Temperature Coefficient(Typ) | - | 700ppm/°C |
Frequently asked questions
What is the main difference between the AD8400ARZ1 and the AD8400AR50?
Both are single-channel, 256-position digital potentiometers from the AD8400 family in an 8-lead SOIC package, but they differ in end-to-end resistance: the AD8400ARZ1 provides a 1 kΩ nominal resistance, while the AD8400AR50 provides a 50 kΩ nominal resistance.
Are the AD8400ARZ1 and AD8400AR50 pin-compatible?
Yes. Both devices are offered in the same 8-lead SOIC (R-8) package and share the same pinout, so they are pin-compatible and can occupy the same PCB land pattern.
Do the AD8400ARZ1 and AD8400AR50 use the same digital interface?
Yes. Both parts use the same 3-wire SPI-compatible serial interface and the same 8-bit code to set the wiper position across 256 positions, so the digital control scheme is identical.
Can the AD8400ARZ1 and AD8400AR50 be substituted for each other in a design?
They are pin- and interface-compatible, but the 50:1 difference in end-to-end resistance (1 kΩ vs 50 kΩ) changes wiper resistance ratio, current handling, and circuit behavior. Substitution is only valid after verifying that the target circuit tolerates the different resistance value against the manufacturer datasheet.
What supply voltage range do the AD8400ARZ1 and AD8400AR50 require?
Both devices operate from a single supply of 2.7 V to 5.5 V, and both support dual-supply operation of ±2.7 V, as specified in the AD8400 datasheet.
How does the resistance tolerance compare between the AD8400ARZ1 and AD8400AR50?
Both parts are specified with a nominal resistance tolerance of ±30%, so the 1 kΩ and 50 kΩ values each carry the same percentage tolerance per the AD8400 datasheet.
Which part should be chosen for a circuit requiring lower wiper current?
The AD8400AR50, with its higher 50 kΩ end-to-end resistance, limits current through the potentiometer more than the 1 kΩ AD8400ARZ1 for a given applied voltage, making it preferable where lower wiper current is required.