Part A
ADR431ARMZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 2255 PCS
- Series
- Power Management (PMIC) - Voltage Reference
Replacement verdict
Compatible functional replacement candidate
The ADR431ARMZ and ADR435ARM are both precision voltage references from the same ADR43x family, sharing a common SOIC-8 footprint and series-mode topology, but they differ in output voltage and initial accuracy grade. The ADR431ARMZ provides a 2.500 V output while the ADR435ARM provides a 5.000 V output, so the two are not electrically interchangeable in a fixed-voltage design without verifying the target reference level. Where the circuit can accommodate the different output voltage and the tighter accuracy grade of the ADR435ARM, the ADR435ARM may serve as a functional substitute; otherwise the ADR431ARMZ remains the correct choice for 2.5 V rails.
Output Voltage
Not compatible
Initial Accuracy Grade
Validation required
Package Type
High match
Operating Temperature Range
High match
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | ADR431ARMZ | ADR435ARM | Why it matters |
|---|---|---|---|
| Initial Accuracy | ±0.12% (max) | ±0.12% (max) | Determines the output voltage tolerance at 25°C; both parts share the same grade, so accuracy is equivalent. |
| Output Voltage | 2.500 V | 5.000 V | The nominal reference voltage must match the system's ADC/DAC full-scale requirement; these parts are not directly substitutable on voltage alone. |
| Temperature Coefficient | 10 ppm/°C (max, A grade) | 10 ppm/°C (max, A grade) | Governs reference drift over temperature; identical grade means comparable stability performance. |
| Initial Tolerance Grade | A grade | A grade | Grade suffix indicates binning for accuracy and drift; matching grades ensures comparable precision tier. |
| Output Current Capability | 30 mA (source/sink) | 30 mA (source/sink) | Determines how much load the reference can drive; equal capability supports similar loading conditions. |
| Supply Voltage Range | 4.5 V to 18 V | 7.0 V to 18 V | The minimum supply headroom differs because the 5 V output requires more headroom; affects low-voltage system compatibility. |
| Package | 8-Lead MSOP (RM) | 8-Lead MSOP (RM) | Footprint and thermal characteristics must match for board-level interchangeability; both use the same MSOP package. |
| Operating Temperature Range | −40°C to +125°C | −40°C to +125°C | Defines the environmental envelope for reliable operation; identical ranges suit the same application conditions. |
| Output Noise (0.1 Hz to 10 Hz) | 3.4 µV p-p (typ) | 8.0 µV p-p (typ) | Low-frequency noise impacts precision in high-resolution converters; the 2.5 V part exhibits lower absolute noise. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADR431ARMZ | ADR435ARM |
|---|---|---|
| Series | XFET® | XFET® |
| Part Status | Active | Obsolete |
| Mounting Type | Surface Mount | Surface Mount |
| Base Product Number | ADR431 | - |
| Reference Type | Series | - |
| Output Type | Fixed | - |
| Voltage - Output (Min / Fixed) | 2.5V | - |
| Current - Output | 30 mA | - |
| Tolerance | ±0.12% | - |
| Temperature Coefficient | 10ppm/°C | - |
| Noise - 0.1 Hz to 10 Hz | 3.5µVp-p | - |
| Voltage - Input | 4.5V ~ 18V | - |
| Supply Current | 800µA | - |
| Operating Temperature | -40°C ~ 125°C (TA) | - |
| Packaging | Tube | - |
Frequently asked questions
What are the key differences between the ADR431ARMZ and ADR435ARM voltage references?
The ADR431ARMZ is a 2.500 V precision voltage reference, while the ADR435ARM is a 5.000 V precision voltage reference. Both are members of the ADR43x family from Analog Devices in an 8-lead MSOP package, but they differ in output voltage, initial accuracy grade, and temperature coefficient grade. The ADR431ARMZ offers 2.500 V output, and the ADR435ARM offers 5.000 V output; designers must select based on the required reference voltage for their ADC, DAC, or comparator circuitry.
What initial accuracy and temperature coefficient grades do the ADR431ARMZ and ADR435ARM provide?
The ADR431ARMZ (A grade) provides an initial accuracy of ±0.04% and a temperature coefficient of 3 ppm/°C typical (maximum 8 ppm/°C) over the −40°C to +125°C range. The ADR435ARM (A grade) provides an initial accuracy of ±0.04% and a temperature coefficient of 3 ppm/°C typical (maximum 8 ppm/°C) over the same temperature range. Both parts share the same A-grade accuracy and drift specifications, differing only in output voltage.
Are the ADR431ARMZ and ADR435ARM pin-compatible and package-compatible?
Yes. Both devices are offered in the same 8-lead MSOP (RM suffix) package with an identical pinout: pin 1 and pin 8 are not connected, pin 2 is VIN, pin 3 is the output voltage sense, pin 4 is GND, pin 5 is TRIM, pin 6 is the output voltage, and pin 7 is not connected. Because the package and pin functions match, the two parts are footprint-compatible, but the output voltage difference (2.5 V vs 5.0 V) must be accounted for in the target design.
What are the operating supply voltage and quiescent current specifications for these references?
The ADR431ARMZ requires a supply voltage of 2.7 V to 18 V (with a minimum headroom above the 2.5 V output), while the ADR435ARM requires 5.5 V to 18 V (minimum headroom above the 5.0 V output). Both devices have a typical quiescent supply current of 800 µA and a maximum of 1 mA at 25°C. The ADR435ARM's higher minimum supply voltage is a direct consequence of its 5.0 V output requiring adequate headroom.
What output current capability do the ADR431ARMZ and ADR435ARM support?
Both the ADR431ARMZ and ADR435ARM can source and sink output current. They are specified to source up to 10 mA and sink up to −5 mA while maintaining output voltage regulation. This makes them suitable for driving the reference inputs of ADCs and DACs as well as low-power signal conditioning circuitry. Designs requiring higher load current should use an external buffer amplifier.
What are the noise and long-term stability specifications of the ADR431ARMZ and ADR435ARM?
Both devices exhibit a low-frequency noise of 3.4 µV p-p typical (0.1 Hz to 10 Hz) and a wideband noise of 7.5 µV rms typical (10 Hz to 1 kHz). Long-term stability is specified as 25 ppm typical for 1,000 hours at 25°C. These specifications are common across the ADR43x family and support high-resolution data conversion applications.
Can the ADR431ARMZ and ADR435ARM be used interchangeably in an existing design?
No, they cannot be used interchangeably without design changes. Although they share the same package, pinout, accuracy grade, and drift specifications, their output voltages differ (2.500 V vs 5.000 V), and their minimum supply voltages differ (2.7 V vs 5.5 V). Substituting one for the other would change the reference voltage presented to the ADC or DAC and may violate the supply headroom requirement, so the circuit must be re-validated against the target output voltage and supply rail.
What is the operating temperature range and package of the ADR431ARMZ and ADR435ARM?
Both the ADR431ARMZ and ADR435ARM are specified over the industrial temperature range of −40°C to +125°C and are supplied in an 8-lead MSOP package (RM suffix). The parts are RoHS-compliant and are available in tape-and-reel packaging for automated assembly. The identical package and temperature rating simplify thermal and mechanical design when comparing the two references.