Part A
ADR4525ARZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 4570 PCS
- Package
- SOIC-8
- Series
- PMIC - Voltage Reference
Replacement verdict
Compatible functional replacement candidate
The ADR4525ARZ and ADR4540ARZ share the same series, package, and pinout, making them a viable functional replacement candidate in designs where the 2.5 V versus 4.096 V output difference is acceptable. The primary distinction is the output voltage, so the replacement should be validated against the target system's reference requirements 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 - 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 | ADR4525ARZ | ADR4540ARZ | Why it matters |
|---|---|---|---|
| Output Voltage | 2.5 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 | ±0.02% | ±0.02% | Initial accuracy determines the untrimmed error at room temperature and directly affects absolute system precision without calibration. |
| Temperature Coefficient | 2 ppm/°C (max) | 2 ppm/°C (max) | Drift over temperature governs how stable the reference remains across the operating range, critical for precision instrumentation. |
| Output Current Capability | ±10 mA | ±10 mA | Source/sink current determines the load the reference can drive while maintaining regulation, affecting buffering requirements. |
| Supply Voltage Range | 3.0 V to 15 V | 3.0 V to 15 V | The allowable supply range must accommodate the system rail and provide sufficient 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 part is guaranteed to meet its specifications. |
| Package | 8-Lead SOIC | 8-Lead SOIC | Package compatibility ensures the part can be placed on the same PCB footprint without layout changes. |
| Supply Current | 950 µA (typ) | 950 µA (typ) | Quiescent current affects total system power budget, important for low-power and portable 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 of high-precision converters and low-noise analog front ends. |
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 | ADR4525ARZ | ADR4540ARZ |
|---|---|---|
| Part Status | Active | Active |
| Reference Type | Series | Series |
| Output Type | Fixed | Fixed |
| Voltage - Output (Min/Fixed) | 2.5V | 4.096V |
| Current - Output | 10 mA | 10 mA |
| Tolerance | ±0.04% | ±0.04% |
| Temperature Coefficient | 4ppm/°C | 4ppm/°C |
| Noise - 01 Hzto10 Hz | 1.25µVp-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 ADR4525ARZ and ADR4540ARZ voltage references?
The ADR4525ARZ provides a fixed 2.5 V output, while the ADR4540ARZ provides a fixed 4.096 V output. Both are members of the ADR45xx family of low-noise, high-accuracy voltage references in an 8-lead SOIC package (R suffix), but they differ in output voltage, initial accuracy grade, and temperature coefficient specifications as defined in their respective datasheets.
Are the ADR4525ARZ and ADR4540ARZ pin-compatible?
Yes. Both devices are offered in the same 8-lead SOIC (R-8) package with identical pin functions, including VIN, VOUT, GND, TRIM, and the optional noise-reduction/filter pin. This allows a common PCB footprint, but the different output voltages must be accounted for in the surrounding circuit design.
What initial output voltage accuracy do these references offer?
The ADR4525ARZ and ADR4540ARZ are both available in A-grade accuracy, specified with an initial output voltage error of ±0.04% maximum at 25°C, per the Analog Devices ADR45xx datasheet. Designers should confirm the exact grade suffix against the manufacturer datasheet for the specific orderable part number.
What temperature coefficient do the ADR4525ARZ and ADR4540ARZ specify?
Both the ADR4525ARZ and ADR4540ARZ are specified with a temperature coefficient of 2 ppm/°C maximum over the −40°C to +125°C operating range, according to the Analog Devices ADR45xx datasheet. This makes them suitable for precision data acquisition and instrumentation applications.
What is the output noise performance of these voltage references?
The ADR45xx family, including the ADR4525ARZ and ADR4540ARZ, is specified with low output voltage noise of 1.25 µV p-p typical (0.1 Hz to 10 Hz) and a noise spectral density of 2.5 nV/√Hz typical at 1 kHz, per the Analog Devices datasheet. An optional noise-reduction capacitor on the NR pin can further lower high-frequency noise.
What is the operating supply voltage and current for the ADR4525ARZ and ADR4540ARZ?
Both devices operate from a supply voltage of 3 V to 15 V and typically draw 950 µA of quiescent current, per the Analog Devices ADR45xx datasheet. The ADR4540ARZ requires a supply voltage at least equal to its 4.096 V output plus the specified dropout, so a minimum supply of approximately 4.5 V is needed in practice.
Can the ADR4525ARZ be used as a drop-in replacement for the ADR4540ARZ?
No, not as a direct functional replacement. Although the packages and pinouts are identical, the output voltages differ (2.5 V versus 4.096 V). A substitution requires revalidation of the system's reference voltage, ADC/DAC full-scale range, and any resistor-divider or bias networks that depend on the reference value.
What are typical applications for the ADR4525ARZ and ADR4540ARZ?
Both references are intended for precision applications such as high-resolution data acquisition systems, medical instrumentation, industrial process control, and precision power supplies. The ADR4525ARZ's 2.5 V output suits systems with 2.5 V or 5 V full-scale ranges, while the ADR4540ARZ's 4.096 V output aligns with 12-, 16-, and 18-bit ADC/DAC full-scale ranges.