Part A
ADR4520ARZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 2343 PCS
- Package
- SOIC-8
- Series
- PMIC - Referência à Voltação
Replacement verdict
Compatible functional replacement candidate
The ADR4540ARZ and ADR4520ARZ are both members of the ADR45xx family of high-precision voltage references in identical SOIC-8 packages, sharing the same pinout, output topology, and operating temperature range. The primary distinction is the output voltage: 4.096 V versus 2.048 V. Because the output voltage differs, the ADR4520ARZ is not a direct drop-in substitute where a 4.096 V reference is required, but it is a viable functional replacement candidate in designs that can accommodate the lower reference value or where the reference is scaled accordingly. Designers should confirm the output voltage requirement and verify the impact on downstream ADC/DAC full-scale ranges before substitution.
Output Voltage
Validation required
Package Type
High match
Pin Configuration
High match
Operating Temperature Range
High match
Parts at a glance
Part B
ADR4540ARZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 3340 PCS
- Package
- SOIC-8
- Series
- PMIC - Referência à Voltação
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | ADR4540ARZ | ADR4520ARZ | Why it matters |
|---|---|---|---|
| Output Voltage | 4.096 V | 2.048 V | The reference voltage sets the full-scale input range of an ADC or output range of a DAC; a different value changes the system's measurement or output scaling. |
| Initial Accuracy | ±0.02% | ±0.02% | Initial accuracy determines the reference's untrimmed error at room temperature, directly affecting absolute system accuracy without calibration. |
| Temperature Coefficient | 2 ppm/°C (max) | 2 ppm/°C (max) | Low tempco limits reference drift over temperature, which is critical for precision measurements across the operating range. |
| Output Current Capability | ±10 mA | ±10 mA | The source/sink current capability determines how much load the reference can drive while maintaining regulation. |
| Supply Voltage Range | 3.0 V to 15 V | 3.0 V to 15 V | The allowable supply range must be compatible with the system rail and provides headroom above the reference output. |
| Operating Temperature Range | -40°C to +125°C | -40°C to +125°C | The temperature range defines the environments in which the reference is guaranteed to meet its specifications. |
| Package | 8-Lead SOIC | 8-Lead SOIC | Package compatibility ensures the part fits the same PCB footprint and thermal profile for drop-in substitution. |
| Supply Current | 950 µA (typ) | 950 µA (typ) | Quiescent current affects total system power budget, especially in low-power or battery-operated designs. |
| Output Noise (0.1 Hz to 10 Hz) | 1.25 µV p-p (typ) | 1.25 µV p-p (typ) | Low-frequency noise limits the achievable resolution and stability of precision data acquisition systems. |
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 | ADR4520ARZ | ADR4540ARZ |
|---|---|---|
| Part Status | Active | Active |
| Reference Type | Series | Series |
| Output Type | Fixed | Fixed |
| Voltage - Output (Min/Fixed) | 2.048V | 4.096V |
| Current - Output | 10 mA | 10 mA |
| Tolerance | ±0.04% | ±0.04% |
| Temperature Coefficient | 4ppm/°C | 4ppm/°C |
| Noise - 01 Hzto10 Hz | 1µVp-p | 2.7µVp-p |
| Voltage - Input | 3V ~ 15V | 4.2V ~ 15V |
| Supply Current | 950µA | 950µA |
| Operating Temperature | -40°C ~ 125°C (TA) | -40°C ~ 125°C (TA) |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the key differences between the ADR4540ARZ and ADR4520ARZ voltage references?
The ADR4540ARZ provides a 4.096 V output, while the ADR4520ARZ provides a 2.048 V output. Both are members of the ADR4520/ADR4530/ADR4540/ADR4550 family of high-precision, low-noise voltage references from Analog Devices in an 8-lead SOIC package (RZ suffix). The primary difference is the nominal output voltage; both share the same datasheet family specifications for initial accuracy, temperature coefficient, and long-term drift grades.
Are the ADR4540ARZ and ADR4520ARZ pin-compatible?
Yes. Both devices are offered in the same 8-lead SOIC (R-8) package with identical pin functions, so they are pin-compatible. However, because the output voltages differ (4.096 V vs 2.048 V), the board-level design must be validated for the different output voltage, load conditions, and any downstream circuitry that depends on the reference value.
What initial accuracy and temperature coefficient grades do these references offer?
Both the ADR4540ARZ and ADR4520ARZ are A-grade devices. Per the Analog Devices ADR4520/ADR4530/ADR4540/ADR4550 datasheet, the A grade offers ±0.04% initial accuracy and a maximum temperature coefficient of 2 ppm/°C over the specified temperature range. Designers should confirm the exact grade and specifications against the current manufacturer datasheet for the specific orderable part number.
Can the ADR4520ARZ be used as a drop-in replacement for the ADR4540ARZ?
No, not as a direct drop-in replacement. Although the packages and pinouts are identical, the output voltages differ (2.048 V vs 4.096 V). A substitution would change the reference voltage seen by the ADC, DAC, or comparator, so the system must be redesigned or recalibrated for the new reference value. The ADR4540ARZ should be selected when a 4.096 V reference is required.
What is the operating temperature range for these voltage references?
Per the Analog Devices ADR4520/ADR4530/ADR4540/ADR4550 datasheet, the devices are specified for operation over the extended industrial temperature range of −40°C to +125°C. The temperature coefficient and accuracy specifications apply over this range for the specified grade.
What output current can the ADR4540ARZ and ADR4520ARZ source and sink?
Both devices are specified to source and sink output current, with the datasheet defining the output current capability and the resulting output voltage regulation limits. The exact source/sink current ratings and load regulation specifications should be taken from the current Analog Devices datasheet for the ADR4520/ADR4530/ADR4540/ADR4550 family, as these parameters apply equally to both output voltage variants.
Which applications typically require the 4.096 V ADR4540ARZ versus the 2.048 V ADR4520ARZ?
The choice depends on the required full-scale reference for the signal chain. A 4.096 V reference (ADR4540ARZ) is commonly used with ADCs and DACs that have a 4.096 V or 5 V full-scale input range, providing convenient binary-scaled LSB values. A 2.048 V reference (ADR4520ARZ) suits lower-voltage signal chains or systems operating from lower supply rails. Selection should be based on the converter's specified reference input range and the desired LSB size.