Part A
ADR4540BRZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 7461 PCS
- Package
- SOIC-8
- Series
- PMIC - Referência à Voltação
Replacement verdict
Compatible functional replacement candidate
The ADR4520ARZ and ADR4540BRZ share the same series voltage reference architecture, package footprint, and pinout, making them functionally interchangeable in many designs. However, the ADR4540BRZ offers a higher output voltage and tighter initial accuracy, so the replacement is only valid where the higher reference voltage and improved precision are acceptable to the surrounding circuit. Designers should confirm that downstream circuitry tolerates the increased output voltage before substituting.
Output Voltage
Validation required
Package Type
High match
Pin Configuration
High match
Initial Accuracy
Validation required
Parts at a glance
Part B
ADR4520ARZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 2343 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 | ADR4520ARZ | ADR4540BRZ | Why it matters |
|---|---|---|---|
| Output Voltage | 2.048 V | 4.096 V | The reference voltage sets the full-scale input range of an ADC or DAC; a different value directly changes the system's measurement or output scaling. |
| Initial Accuracy | ±0.04% (A grade) | ±0.02% (B grade) | Initial accuracy determines the untrimmed error at room temperature; the B grade offers tighter tolerance, improving absolute system precision. |
| Temperature Coefficient | 2 ppm/°C (A grade) | 1 ppm/°C (B grade) | Drift over temperature affects accuracy across the operating range; a lower tempco yields more stable performance in precision applications. |
| Grade / Accuracy Class | A grade | B grade | The grade indicates the guaranteed accuracy and drift specifications; B grade parts are tighter and may be required where A grade cannot meet the error budget. |
| Output Voltage Noise (0.1 Hz to 10 Hz) | 1.25 µV p-p (typical) | 2.5 µV p-p (typical) | Low-frequency noise limits resolution in high-resolution converters; lower noise supports finer measurement capability. |
| Long-Term Drift | 25 ppm/1000 hr (typical) | 25 ppm/1000 hr (typical) | Long-term drift affects calibration stability over the product lifetime; matching values mean similar recalibration intervals. |
| Supply Voltage Range | 3.0 V to 15 V | 3.0 V to 15 V | The supply range must accommodate the system rail; identical ranges allow the same power supply design for either part. |
| Operating Temperature Range | −40 °C to +125 °C | −40 °C to +125 °C | The temperature range defines the environments where the part is guaranteed; identical ranges mean equivalent environmental suitability. |
| Package | 8-Lead SOIC | 8-Lead SOIC | Package compatibility determines whether a part can be dropped into an existing PCB footprint; identical packages allow direct substitution. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADR4540BRZ | ADR4520ARZ |
|---|---|---|
| Part Status | Active | Active |
| Reference Type | Series | Series |
| Output Type | Fixed | Fixed |
| Voltage - Output (Min/Fixed) | 4.096V | 2.048V |
| Current - Output | 10 mA | 10 mA |
| Tolerance | ±0.02% | ±0.04% |
| Temperature Coefficient | 2ppm/°C | 4ppm/°C |
| Noise - 01 Hzto10 Hz | 2.7µVp-p | 1µVp-p |
| Voltage - Input | 4.2V ~ 15V | 3V ~ 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 ADR4520ARZ and ADR4540BRZ voltage references?
The ADR4520ARZ is a 2.048 V output voltage reference with an A-grade initial accuracy of ±0.02% and a maximum temperature coefficient of 1 ppm/°C, housed in an 8-lead SOIC package. The ADR4540BRZ is a 4.096 V output reference with a B-grade initial accuracy of ±0.02% and a maximum temperature coefficient of 2 ppm/°C, also in an 8-lead SOIC package. The primary differences are output voltage (2.048 V vs 4.096 V) and temperature coefficient grade (1 ppm/°C vs 2 ppm/°C).
Are the ADR4520ARZ and ADR4540BRZ pin-compatible?
Yes. Both devices are offered in the same 8-lead SOIC (R-8) package and share the same pinout, including VIN, VOUT, GND, TRIM, and VOUT_SENSE/FORCE pins. This allows a common PCB footprint, but the different output voltages must be accounted for in the circuit design.
Can the ADR4520ARZ be used as a drop-in replacement for the ADR4540BRZ?
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), so the system's reference voltage, ADC/DAC scaling, and any threshold calculations must be redesigned for the new output level. The temperature coefficient grade also differs (1 ppm/°C vs 2 ppm/°C), which may affect precision budget analysis.
What is the initial accuracy specification for each device?
Both the ADR4520ARZ (A grade) and ADR4540BRZ (B grade) specify an initial accuracy of ±0.02% at 25°C. This corresponds to approximately ±0.41 mV for the 2.048 V ADR4520ARZ and approximately ±0.82 mV for the 4.096 V ADR4540BRZ.
How do the temperature coefficients of the ADR4520ARZ and ADR4540BRZ compare?
The ADR4520ARZ (A grade) specifies a maximum temperature coefficient of 1 ppm/°C over the −40°C to +125°C temperature range. The ADR4540BRZ (B grade) specifies a maximum temperature coefficient of 2 ppm/°C over the same range. The ADR4520ARZ therefore offers tighter thermal stability, while the ADR4540BRZ provides a higher output voltage at a slightly relaxed drift specification.
What are the operating temperature ranges and package options for these references?
Both the ADR4520ARZ and ADR4540BRZ are specified over the −40°C to +125°C industrial temperature range and are supplied in the 8-lead SOIC package (R-8 suffix). Both are RoHS-compliant. Designers should confirm the exact ordering code and packaging quantity with the manufacturer's datasheet or an authorized distributor.
Which device should be selected for a 4.096 V ADC reference application?
The ADR4540BRZ should be selected when a 4.096 V reference is required, as it directly provides that output without external gain or level-shifting circuitry. The ADR4520ARZ provides 2.048 V and would require additional amplification to reach 4.096 V, which can introduce additional error and drift. Selection should be based on the ADC's specified reference input range and the system error budget.