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 AD637BR are functionally interchangeable true RMS-to-DC converters sharing the same pinout, package, and core transfer function, with the BR grade offering tighter accuracy and lower input offset specifications. The JR version can serve as a functional substitute where the tighter precision of the BR grade is not mandatory, but accuracy-sensitive designs should validate against the grade-specific error limits before substitution.
Package Type
High match
Pin Configuration
High match
Accuracy Grade
Validation required
Input Offset Voltage
Validation required
Parts at a glance
Part B
AD637BR
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 4669 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 | AD637JR | AD637BR | Why it matters |
|---|---|---|---|
| Grade / Accuracy Grade | J grade (commercial) | B grade (higher accuracy) | The B grade is a premium bin with tighter guaranteed accuracy specifications, so it can be used where the J grade's looser tolerances are insufficient. |
| Total Error (RMS, max) | ±0.5% of reading (typical J-grade spec) | ±0.2% of reading (typical B-grade spec) | Total error directly determines measurement accuracy; the B grade offers roughly half the error of the J grade, affecting whether the part meets a given accuracy budget. |
| Operating Temperature Range | 0°C to +70°C | -40°C to +85°C | The wider industrial temperature range of the B grade allows operation in harsher environments where the commercial J grade is not specified. |
| Package / Mounting | 14-lead SOIC (R suffix) | 14-lead SOIC (R suffix) | Both share the same SOIC footprint, so they are physically interchangeable on an existing PCB layout. |
| Supply Voltage Range | ±3 V to ±18 V (dual supply) | ±3 V to ±18 V (dual supply) | Identical supply requirements mean the same power rail design works for either grade without modification. |
| Input Signal Bandwidth | Up to 8 MHz (typical) | Up to 8 MHz (typical) | Matching bandwidth ensures either grade handles the same AC input frequency content for RMS conversion. |
| Quiescent Supply Current | ~2.2 mA (typical) | ~2.2 mA (typical) | Equivalent current draw means power budget and thermal considerations are unchanged between grades. |
| Output Configuration | Buffered voltage output with dB output | Buffered voltage output with dB output | Same output structure (linear RMS plus logarithmic dB output) preserves circuit topology and downstream interface design. |
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 | AD637JR | AD637BR |
|---|---|---|
| Part Status | Obsolete | Obsolete |
| 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 AD637JR and AD637BR?
The main difference is the grade and specified accuracy. The AD637BR is a higher-grade version with tighter accuracy specifications compared to the AD637JR. Both are RMS-to-DC converters in the same package and are functionally similar, but the BR grade is tested and guaranteed to tighter error limits.
Are the AD637JR and AD637BR pin-compatible?
Yes. Both the AD637JR and AD637BR are offered in the same 16-lead SOIC package with identical pinout, allowing them to be used interchangeably on the same PCB footprint.
What is the accuracy difference between the AD637JR and AD637BR?
The AD637BR grade offers tighter guaranteed accuracy specifications than the AD637JR grade. The BR grade is specified with lower maximum total error over the operating temperature range, making it suitable for higher-precision applications. Designers should consult the AD637 datasheet for the exact error limits of each grade.
Can the AD637JR be replaced by the AD637BR in an existing design?
Yes, in most cases the AD637BR can directly replace the AD637JR because they share the same package, pinout, and functional behavior. The BR grade provides equal or better accuracy, so substitution is generally acceptable, though the design should be validated against the datasheet specifications.
Do both the AD637JR and AD637BR operate over the same temperature range?
Both the AD637JR and AD637BR are specified for the commercial temperature range of 0°C to +70°C. The difference between the grades lies in the guaranteed accuracy limits, not the operating temperature range.
What is the function of the AD637JR and AD637BR?
Both devices are high-accuracy RMS-to-DC converters that compute the true root-mean-square value of an input signal. They are used in applications requiring RMS measurement of complex waveforms, including AC level measurement and signal processing.
Which grade should be selected for a high-precision measurement application?
For high-precision applications, the AD637BR is the preferred choice because it is specified with tighter accuracy limits than the AD637JR. The JR grade is suitable for applications where the wider guaranteed error band is acceptable.