AD737JR-5

Overview

The AD737JR-5 is a low power, precision monolithic true RMS-to-DC converter manufactured by Analog Devices Inc. It computes the true RMS value of an input signal and provides a corresponding DC output voltage. The device features a wide power supply range from ±2.5 V to ±16.5 V and operates within a temperature range of -40°C to +85°C. It offers high accuracy with a maximum error of ±0.2 mV plus 0.3% of reading for sine wave inputs. The component supports direct interfacing with 3½ digit CMOS ADCs and maintains high input impedance of 10^12 Ω with a maximum input bias current of 25 pA.

Feature Summary

• Computes true RMS values for various input waveforms including variable duty cycle pulses
• Provides absolute value computation and average rectified value capabilities
• Features high input impedance and low input bias current for minimal signal loading
• Requires no external trims to achieve specified accuracy levels

Applications

• Upgrading performance of non-RMS precision rectifiers in measurement systems
• Direct interfacing with 3½ digit CMOS analog-to-digital converters
• Measuring triac phase-controlled sine waves and variable duty cycle pulses

Procurement Notes

Verify the specific suffix designation against official Analog Devices documentation to confirm pinout compatibility and electrical tolerances. Ensure that the selected variant matches the required operating temperature range and supply voltage specifications for the target application environment before finalizing procurement decisions.

Selection Notes

Select this component when precise RMS conversion is required for complex waveforms beyond simple sine waves. Consider the negative-going output characteristic and compare it against the positive-output AD736 if polarity constraints exist. Evaluate the low standby current requirement against system power budgets and verify interface compatibility with downstream digital logic or ADCs.

Part Context

The AD737 series represents a family of low-cost, low-power true RMS-to-DC converters designed for precision applications. The JR-5 variant specifically denotes the surface-mount SOIC-8 package configuration with industrial temperature rating. This part serves as a cost-effective alternative to discrete solutions, offering superior accuracy compared to standard precision rectifier circuits while maintaining a compact physical footprint.

Replacement Considerations

The AD736JNZ is a documented substitute providing identical functionality with a positive-going output instead of negative. Verify circuit polarity requirements when substituting, as the internal architecture remains the same but the output stage inversion differs between the two part numbers.