AD737KR-REEL

Overview

The AD737KR-REEL is a low power, precision, monolithic true RMS-to-DC converter manufactured by Analog Devices Inc. It is laser trimmed to provide high accuracy with sine wave inputs and maintains performance across variable duty cycle pulses and phase-controlled sine waves. The device features a wide power supply range of ±2.5 V to ±16.5 V and offers direct interfacing capabilities with 3½ digit CMOS ADCs. It operates with a typical standby current of 25 µA and requires no external trims for specified accuracy.

Feature Summary

• Computes true RMS value from input signals
• Provides average rectified value and absolute value outputs
• Features high input impedance and low input bias current
• Supports signal crest factors up to 5

Applications

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

Procurement Notes

Verify the specific suffix 'KR' against official Analog Devices documentation to confirm tape and reel packaging and temperature grade. Confirm availability status as distribution channels may list limited stock or end-of-life conditions. Ensure the selected variant matches the required operating temperature range and interface specifications for the target application design.

Selection Notes

Select this component when true RMS conversion is required with minimal external trimming. Consider the negative-going output characteristic compared to positive-output alternatives. Evaluate the 200 mV full-scale input range limitation and determine if input scaling is necessary for larger signals. Verify compatibility with the system's power supply voltage constraints within the specified wide range.

Part Context

The AD737 series represents a family of low-cost, low-power true RMS-to-DC converters designed for precision measurement applications. The AD737KR-REEL specifically denotes the reel-packaged version of this monolithic device. It serves as an upgrade path for legacy precision rectifier circuits, offering superior accuracy at comparable or lower costs while maintaining a small physical footprint.

Replacement Considerations

The AD736 is a compatible alternative providing a positive-going output from the same basic device architecture. Verify pinout compatibility and output polarity requirements before substitution. Other RMS-to-DC converters may require different external component configurations or offer varying accuracy specifications.