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 ADR420AR-REEL7 are both precision voltage references from the same ADR42x family, sharing a common SOIC-8 footprint and series-mode topology, but they differ in output voltage, initial accuracy, and temperature coefficient grade. The ADR421BRZ offers a 2.500 V output with tighter B-grade accuracy and lower drift, while the ADR420AR-REEL7 provides a 2.048 V output at A-grade tolerance. Because the output voltage differs, the ADR420AR-REEL7 is not a direct drop-in substitute for the ADR421BRZ in circuits calibrated for 2.500 V; substitution requires recalibration or verification of the reference voltage budget. Where the design can accommodate the 2.048 V reference and relaxed accuracy, the ADR420AR-REEL7 is a viable functional alternative within the same package and family.
Output Voltage
Not compatible
Initial Accuracy
Validation required
Temperature Coefficient
Validation required
Package Type
High match
Parts at a glance
Part B
ADR420AR-REEL7
ADI公司
- Lifecycle
- Active
- Stock
- 5100 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 | ADR420AR-REEL7 | Why it matters |
|---|---|---|---|
| Initial Accuracy | ±0.04% (max) | ±0.15% (max) | Tighter initial tolerance reduces system calibration effort and directly affects output voltage accuracy at room temperature. |
| Output Voltage | 2.500 V | 2.048 V | Different nominal output voltages mean the parts are not directly interchangeable without redesigning the reference rail. |
| Temperature Coefficient | 3 ppm/°C (max) | 10 ppm/°C (max) | Lower tempco yields more stable output over temperature, critical for precision measurement and industrial applications. |
| Initial Accuracy Grade | B grade | A grade | Grade designation reflects binning for accuracy and drift; B grade is a higher-precision bin than A grade. |
| Package | 8-Lead SOIC | 8-Lead SOIC | Identical package and pinout allow drop-in board placement compatibility. |
| Supply Voltage Range | 4.5 V to 18 V | 4.5 V to 18 V | Matching supply range ensures the same power rail can support either device. |
| Operating Temperature Range | -40°C to +125°C | -40°C to +125°C | Same industrial temperature range supports use in identical environmental conditions. |
| Output Current Capability | 10 mA (source/sink) | 10 mA (source/sink) | Load drive capability affects ability to supply downstream circuitry without buffering. |
| Long-Term Drift | 50 ppm/1000 hr (typ) | 50 ppm/1000 hr (typ) | Long-term stability determines recalibration intervals in precision systems. |
| Noise (0.1 Hz to 10 Hz) | 1.75 µV p-p (typ) | 1.75 µV p-p (typ) | Low-frequency noise impacts resolution in high-precision ADC and sensor signal chains. |
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 | ADR420AR-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 ADR420AR-REEL7 voltage references?
The ADR421BRZ is a 2.500 V precision voltage reference in an 8-lead SOIC package with a B-grade initial accuracy of ±0.04% and a low temperature coefficient of 3 ppm/°C max. The ADR420AR-REEL7 is a 2.048 V reference in the same SOIC-8 package, supplied on tape and reel, with A-grade initial accuracy of ±0.15% and a temperature coefficient of 10 ppm/°C max. The primary differences are output voltage (2.500 V vs 2.048 V), accuracy grade, and temperature drift specification.
Are the ADR421BRZ and ADR420AR-REEL7 pin-compatible?
Yes. Both devices are offered in the standard 8-lead SOIC (R-8) package with the same pinout: pin 1 and pin 8 are not connected, pin 2 is VIN, pin 3 is not connected, pin 4 is GND, pin 5 is TRIM, pin 6 is VOUT, and pin 7 is not connected. This allows board-level interchangeability, but the different output voltages must be accounted for in the design.
Can the ADR420AR-REEL7 be used as a drop-in replacement for the ADR421BRZ?
Not directly. Although the packages and pinouts match, the output voltages differ (2.048 V vs 2.500 V), and the accuracy and temperature coefficient grades differ (A-grade vs B-grade). A replacement requires revalidation of the reference voltage, system calibration, and error budget against the target design.
What is the initial accuracy of each device?
The ADR421BRZ offers an initial accuracy of ±0.04% (B-grade). The ADR420AR-REEL7 offers an initial accuracy of ±0.15% (A-grade). These figures are specified at 25°C per the respective manufacturer datasheets.
How do the temperature coefficients of the ADR421BRZ and ADR420AR-REEL7 compare?
The ADR421BRZ specifies a maximum temperature coefficient of 3 ppm/°C over the −40°C to +125°C range. The ADR420AR-REEL7 specifies a maximum temperature coefficient of 10 ppm/°C over the same temperature range. The ADR421BRZ therefore provides tighter drift performance.
What are the operating temperature ranges and supply requirements for these references?
Both the ADR421BRZ and ADR420AR-REEL7 are specified over the −40°C to +125°C industrial temperature range. Both require a minimum supply voltage of 2.7 V and can operate with supplies up to 18 V, with low quiescent current suitable for precision data acquisition and instrumentation applications.
What is the difference in packaging between the ADR421BRZ and ADR420AR-REEL7?
The ADR421BRZ is supplied in an 8-lead SOIC tube or tray format (B-grade, R-8 package). The ADR420AR-REEL7 is supplied in the same 8-lead SOIC package but in tape-and-reel format (7-inch reel), which is intended for automated pick-and-place assembly lines.
Which applications are better suited to each reference?
The ADR421BRZ, with its 2.500 V output and tighter 3 ppm/°C drift, is suited to high-precision data acquisition, precision instrumentation, and 12- to 16-bit ADC/DAC reference applications requiring a 2.5 V rail. The ADR420AR-REEL7, with its 2.048 V output, is commonly used in systems where a 2.048 V reference matches the ADC full-scale range, and its tape-and-reel packaging supports high-volume automated assembly.