Part A
ADR421BRZ
ADI公司
- Lifecycle
- Active
- Stock
- 4766 件
- Package
- SOIC-8
- Series
- PMIC-電壓參攷
Replacement verdict
Compatible functional replacement candidate
The ADR421BRZ and ADR425AR-REEL7 are both precision voltage references from the same ADR42x family, sharing a common SOIC-8 footprint and series-mode topology, which makes the ADR425AR-REEL7 a viable functional replacement candidate for the ADR421BRZ in many designs. However, the two parts differ in output voltage, initial accuracy, and temperature coefficient grade, so the replacement is not a true drop-in substitute. Designers must validate output voltage compatibility, accuracy budget, and thermal drift against the target application before committing to the substitution.
Output Voltage
Validation required
Initial Accuracy
Validation required
Temperature Coefficient
Validation required
Package Type
High match
Parts at a glance
Part B
ADR425AR-REEL7
ADI公司
- Lifecycle
- Active
- Stock
- 3653 件
- Package
- SOIC-N-8
- Series
- PMIC-電壓參攷
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | ADR421BRZ | ADR425AR-REEL7 | Why it matters |
|---|---|---|---|
| Initial Accuracy | ±0.04% (max) | ±0.12% (max) | Tighter initial tolerance reduces system calibration effort and directly affects output voltage accuracy at room temperature. |
| Output Voltage | 2.500 V | 5.000 V | The nominal reference voltage must match the ADC/DAC full-scale requirement; these parts are not directly interchangeable without redesign. |
| Temperature Coefficient | 3 ppm/°C (max) | 10 ppm/°C (max) | Drift over temperature determines accuracy in precision measurement systems operating across wide ambient ranges. |
| Initial Accuracy Grade | B grade | A grade | Grade designation reflects binning for tighter specs; B grade offers better guaranteed performance than A grade. |
| Output Current Capability | 10 mA (source/sink) | 10 mA (source/sink) | Drive capability determines whether the reference can supply the load directly or requires buffering. |
| Supply Voltage Range | 4.5 V to 18 V | 7.0 V to 18 V | Minimum supply headroom differs due to output voltage; the 5 V part requires higher supply, affecting low-voltage system compatibility. |
| Supply Current | 0.8 mA (typ) | 0.8 mA (typ) | Quiescent current impacts power budget in portable and low-power instrumentation designs. |
| Output Noise (0.1 Hz to 10 Hz) | 1.75 µV p-p (typ) | 3.4 µV p-p (typ) | Low-frequency noise limits resolution in high-resolution data acquisition and precision sensor interfaces. |
| Long-Term Drift | 50 ppm/1000 hr (typ) | 50 ppm/1000 hr (typ) | Long-term stability affects recalibration intervals in industrial and instrumentation applications. |
| Package | 8-Lead SOIC | 8-Lead SOIC | Package compatibility determines whether a drop-in board replacement is physically possible. |
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 | ADR421BRZ | ADR425AR-REEL7 |
|---|---|---|
| Series | XFET® | XFET® |
| Part Status | Active | Obsolete |
| Mounting Type | Surface Mount | Surface Mount |
| Reference Type | Series | - |
| Output Type | Fixed | - |
| Voltage - Output (Min/Fixed) | 2.5V | - |
| Current - Output | 10 mA | - |
| Tolerance | ±0.04% | - |
| Temperature Coefficient | 3ppm/°C | - |
| Noise - 01 Hzto10 Hz | 1.75µVp-p | - |
| Voltage - Input | 4.5V ~ 18V | - |
| Supply Current | 600µA | - |
| Operating Temperature | -40°C ~ 125°C (TA) | - |
Frequently asked questions
What are the key differences between the ADR421BRZ and ADR425AR-REEL7 voltage references?
The ADR421BRZ is a 2.500 V precision voltage reference in an 8-lead SOIC package with an initial accuracy of ±0.04% (B grade) and a temperature coefficient of 3 ppm/°C max. The ADR425AR-REEL7 is a 5.000 V precision voltage reference in an 8-lead SOIC package supplied on tape and reel, with an initial accuracy of ±0.12% (A grade) and a temperature coefficient of 10 ppm/°C max. The primary differences are output voltage (2.5 V vs 5.0 V), accuracy grade, and temperature coefficient.
Are the ADR421BRZ and ADR425AR-REEL7 pin-compatible?
Both devices are offered in the same 8-lead SOIC (R-8) package footprint, so the pin assignments and PCB land pattern are compatible. However, because the output voltages differ (2.5 V vs 5.0 V), they are not electrically interchangeable in a given circuit without verifying that the system tolerates the different reference voltage.
What is the initial accuracy of each device?
The ADR421BRZ (B grade) specifies an initial output voltage accuracy of ±0.04% max. The ADR425AR-REEL7 (A grade) specifies an initial accuracy of ±0.12% max. These figures are per the respective Analog Devices datasheets.
How do the temperature coefficients compare?
The ADR421BRZ is specified with a temperature coefficient of 3 ppm/°C max over the −40°C to +125°C range. The ADR425AR-REEL7 is specified with a temperature coefficient of 10 ppm/°C max over the same temperature range. The ADR421BRZ therefore offers tighter drift performance.
What output voltage does each reference provide?
The ADR421BRZ provides a fixed 2.500 V output. The ADR425AR-REEL7 provides a fixed 5.000 V output. The choice between them depends on the required reference level in the target design.
What are the operating temperature ranges for these references?
Both the ADR421BRZ and ADR425AR-REEL7 are specified for operation over the extended industrial temperature range of −40°C to +125°C, per the Analog Devices datasheets.
What does the REEL7 suffix indicate on the ADR425AR-REEL7?
The REEL7 suffix indicates that the ADR425AR is supplied in tape-and-reel packaging (7-inch reel) for automated pick-and-place assembly. The ADR421BRZ is supplied in standard tube or tray packaging; the base part number does not denote tape-and-reel.
Can the ADR421BRZ be used as a drop-in replacement for the ADR425AR-REEL7?
No. Although both share the 8-lead SOIC package, the output voltages differ (2.500 V vs 5.000 V), so a direct substitution would change the reference level seen by the load. Replacement requires revalidation of the circuit against the different output voltage, accuracy, and drift specifications.