Part A
ADR420BRZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 6197 PCS
- Package
- SOIC-8
- Series
- PMIC - Referência à Voltação
Replacement verdict
Compatible functional replacement candidate
The ADR420BRZ and ADR421BR-REEL7 are both precision voltage references from the same ADR42x family, sharing identical package, pinout, and output topology, but they differ in output voltage and initial accuracy grade. The ADR420BRZ provides a 2.048 V output while the ADR421BR-REEL7 provides 2.500 V, so the two are not electrically interchangeable in a fixed-reference design without verifying the system's reference voltage requirement. Where the circuit can accommodate the different output voltage and the tighter initial accuracy tolerance of the ADR421BR-REEL7, the ADR421BR-REEL7 can serve as a functional replacement candidate, subject to validation of the reference voltage budget and load conditions.
Output Voltage
Validation required
Package Type
High match
Pin Configuration
High match
Initial Accuracy Grade
Validation required
Parts at a glance
Part B
ADR421BR-REEL7
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 5856 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 | ADR420BRZ | ADR421BR-REEL7 | Why it matters |
|---|---|---|---|
| Output Voltage | 2.048 V | 2.500 V | The reference voltage sets the full-scale value of the ADC/DAC; a different output voltage changes the system's measurement range and scaling. |
| Initial Accuracy | ±0.04% (max) | ±0.04% (max) | Initial accuracy determines the untrimmed error at room temperature and directly affects system precision without calibration. |
| Temperature Coefficient | 3 ppm/°C (max) | 3 ppm/°C (max) | Drift over temperature dominates total error in precision systems; matching tempco ensures comparable stability across the operating range. |
| Output Current Capability | ±10 mA (source/sink) | ±10 mA (source/sink) | Determines the load the reference can drive directly; identical capability means the same external buffering requirements apply. |
| Supply Voltage Range | 4.5 V to 18 V | 4.5 V to 18 V | The allowable supply window must match the system rail; identical ranges allow drop-in use in the same power architecture. |
| Supply Current | 0.8 mA (typ) | 0.8 mA (typ) | Quiescent current affects power budget in low-power designs; equal consumption means no change in thermal or battery-life calculations. |
| Output Noise (0.1 Hz to 10 Hz) | 1.75 µV p-p (typ) | 1.75 µV p-p (typ) | Low-frequency noise limits resolution in high-resolution converters; matching noise keeps achievable effective bits unchanged. |
| Long-Term Drift | 50 ppm/1000 hr (typ) | 50 ppm/1000 hr (typ) | Long-term stability determines recalibration intervals; identical drift means the same maintenance schedule can be retained. |
| Package | 8-Lead SOIC | 8-Lead SOIC | Package compatibility ensures the same PCB footprint and assembly process can be used without layout changes. |
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 | ADR420BRZ | ADR421BR-REEL7 |
|---|---|---|
| Series | XFET® | XFET® |
| Part Status | Active | Obsolete |
| Reference Type | Series | Series |
| Output Type | Fixed | Fixed |
| Voltage - Output (Min/Fixed) | 2.048V | 2.5V |
| Current - Output | 10 mA | 10 mA |
| Tolerance | ±0.05% | ±0.04% |
| Temperature Coefficient | 3ppm/°C | 3ppm/°C |
| Noise - 01 Hzto10 Hz | 1.75µVp-p | 1.75µVp-p |
| Voltage - Input | 4V ~ 18V | 4.5V ~ 18V |
| Supply Current | 600µA | 600µA |
| 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 ADR420BRZ and ADR421BR-REEL7 voltage references?
The ADR420BRZ is a 2.048 V precision voltage reference in an 8-lead SOIC package (RZ suffix), while the ADR421BR-REEL7 is a 2.500 V precision voltage reference in an 8-lead SOIC package supplied on a 7-inch tape and reel. Both are members of the ADR42x family from Analog Devices and share the same architecture, grade (B grade, ±0.04% initial accuracy typical), and temperature coefficient class, but they differ in output voltage and packaging format.
Are the ADR420BRZ and ADR421BR-REEL7 pin-compatible?
Yes. Both devices are offered in the same 8-lead SOIC (R-8) package with identical pin functions: 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. Because the pinout and package footprint are the same, they are physically interchangeable on a PCB, but the output voltage difference (2.048 V vs 2.500 V) must be accounted for in the design.
What is the initial accuracy of the ADR420BRZ and ADR421BR-REEL7?
Both the ADR420BRZ and ADR421BR-REEL7 are B-grade devices with an initial accuracy of ±0.04% maximum at 25°C, per the Analog Devices ADR420/ADR421/ADR423/ADR425 datasheet. This corresponds to approximately ±0.8 mV for the 2.048 V ADR420BRZ and approximately ±1.0 mV for the 2.500 V ADR421BR-REEL7.
What temperature coefficient do the ADR420BRZ and ADR421BR-REEL7 specify?
Both B-grade parts are specified with a temperature coefficient of 3 ppm/°C maximum over the −40°C to +125°C operating temperature range, according to the Analog Devices ADR42x datasheet. The ADR420BRZ and ADR421BR-REEL7 therefore share the same temperature stability class.
What is the difference between the "BRZ" and "BR-REEL7" suffixes?
The "BRZ" suffix on the ADR420BRZ indicates a B-grade device in an 8-lead SOIC package (R) supplied in tube or tray form (Z denotes the lead-free/RoHS-compliant SOIC package). The "BR-REEL7" suffix on the ADR421BR-REEL7 indicates a B-grade device in the same 8-lead SOIC package supplied on a 7-inch tape and reel for automated assembly. The electrical grade and package are the same; only the shipping format differs.
Can the ADR420BRZ be used as a drop-in replacement for the ADR421BR-REEL7?
Physically and pin-wise, yes, since both use the same 8-lead SOIC footprint. However, they are not electrically equivalent: the ADR420BRZ provides a 2.048 V output while the ADR421BR-REEL7 provides 2.500 V. A direct substitution is only valid if the target circuit is designed for the corresponding output voltage and the reference voltage change is acceptable. The output voltage difference must be validated against the system requirements before substitution.
What are the operating temperature ranges and supply voltage requirements for these references?
Both the ADR420BRZ and ADR421BR-REEL7 are specified over the −40°C to +125°C extended industrial temperature range. Per the Analog Devices ADR42x datasheet, the devices operate from a supply voltage of 2.7 V to 18 V (VIN), with a specified minimum supply headroom above the output voltage. Designers should confirm the exact VIN range and headroom requirements in the datasheet for the chosen output voltage.
What output current can the ADR420BRZ and ADR421BR-REEL7 source and sink?
Per the Analog Devices ADR42x datasheet, both devices can source up to 10 mA and sink up to −5 mA (i.e., 5 mA sink capability) at the VOUT pin while maintaining specified accuracy. The short-circuit current is limited internally. These figures apply to both the ADR420BRZ and ADR421BR-REEL7 since they share the same output stage design.