AD737KRZ-RL

Overview

The AD737KRZ-RL is a low power, precision, monolithic true RMS-to-DC converter manufactured by Analog Devices Inc. It is laser trimmed to provide a maximum error of ±0.2 mV ± 0.3% of reading with sine wave inputs. The device computes the true RMS value and provides a negative-going output voltage proportional to the RMS value of the input signal. It features a wide power supply range from ±2.5 V to ±16.5 V and maintains high accuracy while measuring a wide range of input waveforms, including variable duty cycle pulses and triac-controlled sine waves.

Feature Summary

• Computes true RMS value for accurate measurement of complex waveforms
• High input impedance with low input bias current for minimal signal loading
• Direct interfacing capability with standard digital displays or ADCs
• Requires no external trims for specified accuracy

Applications

• Upgrading performance of non-RMS precision rectifiers
• Measurement of variable duty cycle pulses
• Analysis of triac phase-controlled sine waves
• Integration with 3½ digit CMOS ADCs

Procurement Notes

Verify the specific suffix 'KRZ-RL' against the official Analog Devices datasheet to confirm temperature grade and reel packaging specifications. Ensure compatibility with system requirements for negative-going output signals. Confirm availability status as distribution channels may vary. Validate RoHS compliance documentation prior to integration into final products.

Selection Notes

Select this component when precise RMS conversion of non-sinusoidal signals is required without external calibration. Consider the negative output polarity relative to system ground references. Evaluate the ±0.2 mV ± 0.3% accuracy specification against application tolerance levels. Assess the low standby current benefit for battery-powered designs compared to alternative precision rectifier circuits.

Part Context

The AD737 series represents a family of true RMS-to-DC converters designed for cost-effective precision measurements. The AD737 specifically provides a negative output, distinguishing it from the positive-output AD736 variant. This monolithic solution eliminates the need for multiple discrete components typically required in traditional RMS conversion architectures, offering a compact and reliable alternative for signal processing applications.

Replacement Considerations

The AD736 serves as a functional substitute if a positive-going output signal is preferred over the AD737's negative output. Both devices share identical internal architecture and accuracy specifications. Verify pinout compatibility and output polarity requirements before substituting.