Part A
AD637JR
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 6307 PCS
- Package
- SOIC-16
- Series
- Convertisseur PMIC - RMS vers DC
Replacement verdict
Compatible functional replacement candidate
The AD637JR and AD637BRZ are functionally equivalent true RMS-to-DC converters sharing the same core architecture, pinout, and package, making the AD637JR a viable functional substitute for the AD637BRZ in most applications. The primary distinction lies in grade-level accuracy specifications, where the AD637BRZ offers tighter guaranteed linearity and accuracy tolerances, while the AD637JR provides a wider specified operating temperature range. Designers should validate precision-critical signal chains against the looser JR-grade error budget before committing to substitution.
Package Type
High match
Pin Configuration
High match
Accuracy Grade
Validation required
Operating Temperature Range
Validation required
Parts at a glance
Part B
AD637BRZ
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 4738 PCS
- Package
- SOIC-16
- Series
- Convertisseur PMIC - RMS vers DC
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 | AD637JR | Why it matters |
|---|---|---|---|
| Grade / Temperature Range | B grade, -40°C to +85°C | J grade, 0°C to +70°C | The B grade is specified over the industrial temperature range, while the J grade is limited to commercial temperatures; this affects suitability for harsh or outdoor environments. |
| Accuracy (Max Total Error) | ±0.5% (B grade) | ±1.0% (J grade) | Tighter accuracy in the B grade yields more precise RMS measurements, which is critical for instrumentation and calibration applications. |
| Package / Mounting | 20-Lead SOIC (R-20), surface mount | 20-Lead SOIC (R-20), surface mount | Both share the same SOIC footprint, so board layout is compatible, but the suffix Z denotes RoHS-compliant lead finish on the BRZ. |
| RoHS Compliance | RoHS compliant (Z suffix) | Non-RoHS (legacy lead finish) | RoHS compliance is required for products sold into the EU and many other markets; the JR may not meet current environmental regulations. |
| Supply Voltage Range | ±3 V to ±18 V (dual supply) | ±3 V to ±18 V (dual supply) | Identical supply range means both parts can be used in the same power architecture without redesign. |
| Bandwidth | 8 MHz (at 2 V RMS) | 8 MHz (at 2 V RMS) | Matching bandwidth ensures equivalent AC signal handling capability for RMS-to-DC conversion. |
| Input Voltage Range | 0 to 7 V RMS (full scale) | 0 to 7 V RMS (full scale) | Same full-scale input range allows direct substitution in measurement front-ends. |
| Operating Current | 2.2 mA typical | 2.2 mA typical | Equivalent quiescent current means no change in power budget when swapping parts. |
| Output Type | Voltage output (buffered) | Voltage output (buffered) | Buffered voltage output provides low output impedance and direct interface to ADCs in both variants. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD637JR | AD637BRZ |
|---|---|---|
| Part Status | Obsolete | 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 are the primary differences between the AD637BRZ and AD637JR?
The AD637BRZ and AD637JR are both RMS-to-DC converters from Analog Devices, but they differ in grade and package. The AD637BRZ is a higher-grade industrial version specified over the −40°C to +85°C temperature range and supplied in a 16-lead SOIC (R-16) package. The AD637JR is a commercial-grade version specified over 0°C to +70°C and supplied in a 16-lead SOIC package. The BRZ grade offers tighter accuracy specifications than the JR grade.
Are the AD637BRZ and AD637JR pin-compatible?
Yes. Both the AD637BRZ and AD637JR are offered in the same 16-lead SOIC package with identical pin functions, so they are pin-compatible. The difference lies in the temperature grade and accuracy specifications, not the pinout.
What is the operating temperature range for each part?
The AD637BRZ is specified for the industrial temperature range of −40°C to +85°C. The AD637JR is specified for the commercial temperature range of 0°C to +70°C. Designs exposed to sub-zero or elevated ambient conditions should use the BRZ grade.
How do the accuracy specifications compare between the AD637BRZ and AD637JR?
The AD637BRZ is the higher-grade device and carries tighter accuracy specifications than the AD637JR. The BRZ grade is characterized for lower total error over its wider temperature range, while the JR grade is specified for commercial temperature operation. Designers requiring precision RMS measurement across the full industrial range should select the BRZ grade.
Can the AD637JR be used as a drop-in replacement for the AD637BRZ?
Functionally and pin-wise, the AD637JR can replace the AD637BRZ in the same 16-lead SOIC footprint. However, the JR grade is only specified over 0°C to +70°C and has looser accuracy specifications, so it is not a valid substitute in applications requiring industrial temperature operation or the tighter BRZ accuracy limits. The substitution must be validated against the target design's temperature and accuracy requirements.
What is the function of the AD637 series devices?
The AD637 is a complete, high-accuracy monolithic RMS-to-DC converter that computes the true root-mean-square value of an arbitrary input waveform. It provides a DC output proportional to the RMS value and is used in instrumentation, power measurement, and signal-processing applications requiring true RMS conversion.
Do both parts share the same supply and package configuration?
Yes. Both the AD637BRZ and AD637JR operate from the same dual-supply configuration and are housed in the same 16-lead SOIC package. The distinguishing factors are the temperature grade and the associated accuracy specifications, not the supply or package configuration.