Part A
ADR431ARMZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 2255 PCS
- Series
- Power Management (PMIC) - Voltage Reference
Replacement verdict
Compatible functional replacement candidate
The ADR435BRMZ and ADR431ARMZ 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 ADR435BRMZ provides a 5.0 V output with tighter B-grade accuracy, while the ADR431ARMZ provides a 2.5 V output at A-grade accuracy, so substitution is only viable where the circuit can accommodate the different reference voltage and the relaxed accuracy tolerance.
Output Voltage
Validation required
Initial Accuracy Grade
Validation required
Package Type
High match
Operating Temperature Range
High match
Parts at a glance
Part B
ADR435BRMZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 4871 PCS
- Package
- MSOP-8
- Series
- PMIC - Voltage Reference
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | ADR435BRMZ | ADR431ARMZ | Why it matters |
|---|---|---|---|
| Output Voltage | 5.0 V | 2.5 V | The nominal reference voltage determines the full-scale range of the ADC/DAC and cannot be substituted without recalibration. |
| Initial Accuracy | ±0.04% (B grade) | ±0.12% (A grade) | Tighter initial accuracy reduces system calibration effort and directly affects measurement precision. |
| Temperature Coefficient | 3 ppm/°C max (B grade) | 10 ppm/°C max (A grade) | Drift over temperature dominates total error in precision systems; lower TC yields more stable readings across the operating range. |
| Output Noise (0.1–10 Hz) | 8 µV p-p typ | 3.4 µV p-p typ | Low-frequency noise limits resolution for high-resolution converters and precision instrumentation. |
| Long-Term Drift | 25 ppm/1000 h typ | 25 ppm/1000 h typ | Long-term stability determines how often the system requires recalibration over its lifetime. |
| Supply Voltage Range | 7.0 V to 18 V | 4.5 V to 18 V | The minimum supply headroom constrains the system rail design and low-voltage operation. |
| Quiescent Current | 800 µA typ | 800 µA typ | Supply current affects power budget in portable and low-power designs. |
| Output Current Capability | ±10 mA | ±30 mA | Source/sink capability determines whether the reference can drive external loads directly without buffering. |
| Package | 8-Lead MSOP | 8-Lead MSOP | Package footprint and pinout must match for a drop-in board-level substitution. |
| Operating Temperature Range | −40 °C to +125 °C | −40 °C to +125 °C | The rated temperature range must cover the application environment for guaranteed performance. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADR431ARMZ | ADR435BRMZ |
|---|---|---|
| Series | XFET® | XFET® |
| Part Status | Active | Active |
| Base Product Number | ADR431 | - |
| Reference Type | Series | Series |
| Output Type | Fixed | Fixed |
| Voltage - Output (Min / Fixed) | 2.5V | - |
| Current - Output | 30 mA | 30 mA |
| Tolerance | ±0.12% | ±0.04% |
| Temperature Coefficient | 10ppm/°C | 3ppm/°C |
| Noise - 0.1 Hz to 10 Hz | 3.5µVp-p | - |
| Voltage - Input | 4.5V ~ 18V | 7V ~ 18V |
| Supply Current | 800µA | 800µA |
| Operating Temperature | -40°C ~ 125°C (TA) | -40°C ~ 125°C (TA) |
| Mounting Type | Surface Mount | Surface Mount |
| Packaging | Tube | - |
| Voltage - Output (Min/Fixed) | - | 5V |
| Noise - 01 Hzto10 Hz | - | 8µVp-p |
Frequently asked questions
What are the key differences between the ADR435BRMZ and ADR431ARMZ voltage references?
The ADR435BRMZ provides a fixed 5.000 V output with an initial accuracy of ±0.04% (B grade) and a maximum temperature coefficient of 3 ppm/°C, while the ADR431ARMZ provides a fixed 2.500 V output with an initial accuracy of ±0.04% (A grade) and a maximum temperature coefficient of 10 ppm/°C. Both are series-mode references in 8-lead MSOP packages, but they differ in output voltage and temperature drift grade.
Are the ADR435BRMZ and ADR431ARMZ pin-compatible?
Yes. Both devices are offered in the same 8-lead MSOP (RM-8) package and share the same pinout, including VIN, VOUT, GND, TRIM, and VOUT SENSE/FORCE pins. However, pin compatibility does not guarantee functional interchangeability because the output voltages differ (5.000 V vs 2.500 V).
Can the ADR435BRMZ be used as a direct replacement for the ADR431ARMZ?
No. The ADR435BRMZ outputs 5.000 V while the ADR431ARMZ outputs 2.500 V, so a direct substitution would change the reference voltage seen by the downstream circuit. Replacement requires verifying that the system tolerates the doubled reference voltage and that the ADR435BRMZ's 3 ppm/°C drift and supply headroom requirements are acceptable.
What are the initial accuracy specifications of the ADR435BRMZ and ADR431ARMZ?
The ADR435BRMZ (B grade) has an initial accuracy of ±0.04% maximum, corresponding to ±2 mV at 5.000 V. The ADR431ARMZ (A grade) has an initial accuracy of ±0.04% maximum, corresponding to ±1 mV at 2.500 V. Both grades are specified at 25°C.
How do the temperature coefficients of the ADR435BRMZ and ADR431ARMZ compare?
The ADR435BRMZ B grade is specified with a maximum temperature coefficient of 3 ppm/°C over the −40°C to +125°C range. The ADR431ARMZ A grade is specified with a maximum temperature coefficient of 10 ppm/°C over the same temperature range. The ADR435BRMZ therefore offers tighter drift performance.
What output current can the ADR435BRMZ and ADR431ARMZ source and sink?
Both the ADR435BRMZ and ADR431ARMZ can source up to 10 mA and sink up to 10 mA at their respective output voltages, subject to the specified output voltage accuracy and thermal limits. Designers should consult the manufacturer datasheet for the exact load regulation and dropout conditions.
What supply voltage range is required for the ADR435BRMZ and ADR431ARMZ?
The ADR435BRMZ requires a minimum supply voltage of 5.5 V (VOUT + 0.5 V headroom) and operates up to 18 V. The ADR431ARMZ requires a minimum supply voltage of 3.0 V (VOUT + 0.5 V headroom) and operates up to 18 V. The lower output voltage of the ADR431ARMZ allows operation from lower supply rails.
What are the typical applications for the ADR435BRMZ versus the ADR431ARMZ?
The ADR435BRMZ (5.000 V, 3 ppm/°C) is typically used in precision data acquisition systems, high-resolution ADCs/DACs, and industrial instrumentation requiring a 5 V reference. The ADR431ARMZ (2.500 V, 10 ppm/°C) is typically used in portable instrumentation, 3 V/5 V mixed-signal systems, and applications where a 2.5 V reference with moderate drift is sufficient.