Part A
AD637ARZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 7762 PCS
- Package
- SOIC-16
- Series
- PMIC - RMS to DC Converters
Replacement verdict
Compatible functional replacement candidate
The AD637BRZ and AD637ARZ are functionally interchangeable true RMS-to-DC converters sharing the same core architecture, pinout, and package, with the BRZ grade offering tighter accuracy and lower input offset specifications. The ARZ can serve as a functional substitute where the tighter BRZ-grade precision is not mandatory, while the BRZ remains the preferred choice for high-accuracy measurement applications.
Package Type
High match
Pin Configuration
High match
Accuracy Grade
Validation required
Operating Temperature Range
High match
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD637BRZ | AD637ARZ | Why it matters |
|---|---|---|---|
| Grade / Accuracy Grade | B grade (higher accuracy) | A grade (standard accuracy) | The grade determines the guaranteed accuracy specifications; B grade offers tighter tolerances than A grade, affecting measurement precision in RMS-to-DC conversion. |
| Total Error (RMS/DC Conversion) | ±0.5% max (B grade) | ±1.0% max (A grade) | Total error directly bounds the worst-case accuracy of the RMS measurement, which is critical for precision instrumentation and calibration applications. |
| Nonlinearity | ±0.02% max | ±0.05% max | Nonlinearity affects fidelity across the input signal range; lower nonlinearity yields more consistent readings at different signal amplitudes. |
| Operating Temperature Range | -40°C to +85°C | 0°C to +70°C | The wider industrial temperature range of the B grade allows use in harsher environments, while the A grade is limited to commercial temperature ranges. |
| Package / Mounting | 20-Lead SOIC (R-20) | 20-Lead SOIC (R-20) | Package and footprint compatibility ensures the parts are physically interchangeable on the same PCB layout. |
| Supply Voltage Range | ±3 V to ±18 V (dual supply) | ±3 V to ±18 V (dual supply) | Identical supply requirements mean both parts can operate in the same power architecture without redesign. |
| Bandwidth | 8 MHz (at 200 mV rms) | 8 MHz (at 200 mV rms) | Bandwidth determines the maximum signal frequency the RMS converter can accurately process; matching values confirm equivalent dynamic performance. |
| Input Voltage Range | 0 to 7 V rms (full scale) | 0 to 7 V rms (full scale) | The full-scale input range defines the maximum measurable RMS signal; identical ranges ensure equivalent measurement capability. |
| Quiescent Supply Current | 2.2 mA typ | 2.2 mA typ | Supply current affects power budget and thermal design; matching values indicate equivalent power consumption. |
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 | AD637ARZ | AD637BRZ |
|---|---|---|
| Part Status | Active | Active |
| Supply Current | 2.2 mA | 2.2 mA |
| Voltage - Supply | ±3V ~ 18V | ±3V ~ 18V |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What is the primary difference between the AD637BRZ and AD637ARZ?
The main difference is the specified accuracy grade. The AD637BRZ is the higher-grade version with tighter accuracy specifications, while the AD637ARZ is the standard-grade version. Both are RMS-to-DC converters in the same 16-lead SOIC package and share the same functional architecture.
Are the AD637BRZ and AD637ARZ pin-compatible?
Yes. Both devices are offered in the same 16-lead SOIC (R-16) package and share the same pinout, so they are pin-compatible and can be used on the same PCB land pattern.
Do the AD637BRZ and AD637ARZ have the same operating temperature range?
Both the AD637BRZ and AD637ARZ are specified over the industrial temperature range of −40°C to +85°C, per the Analog Devices datasheet.
What supply voltage do the AD637BRZ and AD637ARZ require?
Both devices operate from dual supplies of ±3 V to ±18 V, consistent with the AD637 datasheet specifications. The supply requirements are identical between the B and A grades.
Can the AD637ARZ be used as a drop-in replacement for the AD637BRZ?
Because they are pin-compatible and functionally identical, the AD637ARZ can be used in place of the AD637BRZ only if the looser accuracy grade of the A version still meets the design's error budget. The B grade offers tighter accuracy, so substituting downward may degrade measurement precision.
What bandwidth do the AD637BRZ and AD637ARZ support?
Both grades share the same AD637 signal processing core and are specified for RMS computation with a 2 MHz bandwidth for the AD637, as stated in the Analog Devices datasheet. Bandwidth is a function of the core design and is the same for both grades.
Are the AD637BRZ and AD637ARZ RoHS compliant?
Yes. The "Z" suffix in both part numbers denotes RoHS-compliant packaging per Analog Devices nomenclature, so both the AD637BRZ and AD637ARZ are RoHS compliant.