Part A
AD637JRZ-RL
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 7145 PCS
- Package
- SOIC-16
- Series
- Convertisseur PMIC - RMS vers DC
Replacement verdict
Compatible functional replacement candidate
The AD637JRZ-RL and AD637KR are both true RMS-to-DC converters from the same AD637 family, sharing the same core conversion function and 14-lead SOIC package. The AD637JRZ-RL is the RoHS-compliant tape-and-reel variant, while the AD637KR is the commercial-grade version. Functionally they are strong candidates for substitution, though grade-dependent accuracy specifications and supply/screening differences should be validated against the target application requirements.
Core Function
High match
Package Type
High match
Accuracy Grade
Validation required
Compliance and Packaging
Validation required
Parts at a glance
Part B
AD637KR
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 5379 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 | AD637JRZ-RL | AD637KR | Why it matters |
|---|---|---|---|
| Package / Case | 16-Lead SOIC (Wide, 300 mil) | 16-Lead SOIC (Wide, 300 mil) | Package must match the PCB footprint for direct drop-in substitution; both share the same SOIC-16W body. |
| Temperature Grade / Operating Range | Commercial (0°C to +70°C) | Commercial (0°C to +70°C) | Operating temperature range determines suitability for the target environment; both are commercial-grade. |
| Accuracy (Max Total Error) | ±0.5% of reading (J grade) | ±0.2% of reading (K grade) | The K grade offers tighter accuracy than the J grade, affecting measurement precision in RMS-to-DC conversion. |
| Bandwidth (RMS Conversion) | 8 MHz (at 200 mV rms) | 8 MHz (at 200 mV rms) | Bandwidth defines the maximum input frequency the RMS converter can accurately process; both are identical. |
| Supply Voltage (Dual) | ±3 V to ±18 V | ±3 V to ±18 V | Supply range must be compatible with the system rails; both support the same dual-supply window. |
| Supply Current | 2.2 mA (typical) | 2.2 mA (typical) | Quiescent current impacts power budget; both draw the same typical supply current. |
| Input Voltage Range | ±10 V (with ±15 V supplies) | ±10 V (with ±15 V supplies) | Input range determines the maximum signal amplitude that can be measured without clipping; both are identical. |
| Output Type | Voltage output (buffered) | Voltage output (buffered) | Output configuration must match the downstream ADC or signal chain; both provide a buffered voltage output. |
| Packaging / Ordering | Tape & Reel (RL) | Tube / bulk | Packaging affects assembly line handling and inventory; the RL suffix denotes tape-and-reel versus tube. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD637JRZ-RL | AD637KR |
|---|---|---|
| Part Status | Active | Obsolete |
| Supply Current | 2.2 mA | 2.2 mA |
| Voltage - Supply | ±3V ~ 18V | ±3.0V ~ 18V |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the key differences between the AD637JRZ-RL and the AD637KR?
Both devices are RMS-to-DC converters from the AD637 series, but they differ in grade and packaging. The AD637JRZ-RL is a commercial-grade (0°C to 70°C) device supplied in a 16-lead SOIC package in tape-and-reel form, while the AD637KR is a commercial-grade device supplied in a 14-lead CERDIP (hermetic ceramic dual in-line) package. The AD637KR offers a wider operating temperature range of 0°C to 70°C in a through-hole ceramic package, whereas the AD637JRZ-RL is a surface-mount SOIC variant.
Are the AD637JRZ-RL and AD637KR functionally interchangeable?
Functionally, both are true RMS-to-DC converters with the same core transfer function and accuracy specifications for computing RMS values of AC signals. However, they are not pin-for-pin or package-compatible: the AD637JRZ-RL uses a 16-lead SOIC footprint, and the AD637KR uses a 14-lead CERDIP footprint. A direct drop-in substitution is not possible without a PCB redesign or adapter, and any substitution must be validated against the manufacturer datasheet for the specific grade and package.
What is the accuracy specification for these AD637 devices?
Per the Analog Devices AD637 datasheet, the AD637 provides high accuracy true RMS conversion with a maximum total error of 0.5% of reading plus 0.5 mV for the J and K grades when measuring a full-scale input. The devices feature a wide bandwidth and can compute the RMS value of complex waveforms with crest factors up to 10 with minimal additional error. Designers should consult the specific grade datasheet for exact error budgets over temperature.
What are the package and mounting differences between the AD637JRZ-RL and AD637KR?
The AD637JRZ-RL is housed in a 16-lead SOIC (small outline integrated circuit) surface-mount package, supplied in tape-and-reel for automated assembly. The AD637KR is housed in a 14-lead CERDIP, a hermetic ceramic dual in-line through-hole package. The CERDIP package offers hermeticity and is suited to through-hole or socketed assembly, while the SOIC package supports compact surface-mount PCB layouts.
What is the operating temperature range for the AD637JRZ-RL and AD637KR?
Both the AD637JRZ-RL and AD637KR are specified for commercial temperature operation from 0°C to 70°C. The "J" and "K" grade designators in the AD637 series correspond to commercial temperature grades. For extended temperature operation, other AD637 grades (such as A or B grades) should be considered per the manufacturer datasheet.
What supply voltage do the AD637JRZ-RL and AD637KR require?
The AD637 series operates from dual supplies, typically ±15 V, with a specified supply range of ±3 V to ±18 V per the Analog Devices datasheet. Both the AD637JRZ-RL and AD637KR support this dual-supply configuration. The devices also provide a buffered voltage output and can be configured for dB output and chip-select operation.
Can the AD637JRZ-RL be used as a replacement for the AD637KR in an existing design?
Not as a direct drop-in replacement. The AD637JRZ-RL is a 16-lead SOIC surface-mount device, while the AD637KR is a 14-lead CERDIP through-hole device, so the PCB footprints and pin counts differ. Electrical performance for RMS conversion is comparable for the same grade, but the designer must verify pin functions, layout, thermal considerations, and package-specific derating against the Analog Devices datasheet before substituting one for the other.
What are the typical applications for the AD637JRZ-RL and AD637KR?
Both devices are used for precision true RMS-to-DC conversion in applications such as panel meters, instrumentation, power measurement, audio level detection, and signal processing where accurate RMS values of complex waveforms are required. The AD637KR's hermetic CERDIP package suits harsh or high-reliability environments, while the AD637JRZ-RL's SOIC package suits compact surface-mount designs. Application suitability should be confirmed against the manufacturer datasheet for each package and grade.