AD737KR

Overview

The AD737KR 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 is laser trimmed to ensure high accuracy with a maximum error specification of ±0.2 mV plus 0.3% of the reading for sine wave inputs. It supports a wide dynamic range with a 200 mV full-scale input capability and maintains performance across various waveform types, including variable duty cycle pulses and phase-controlled sine waves.

Feature Summary

• Computes true RMS values directly using signal squaring and integration techniques rather than rectification and averaging
• Provides direct interfacing capabilities with standard digital display systems such as 3½ digit CMOS ADCs
• Features high input impedance and low input bias current to minimize loading effects on source circuits

Applications

• Upgrading non-RMS precision rectifiers in measurement instruments
• Signal analysis for variable duty cycle pulse waveforms
• Measurement of triac phase-controlled sine waves

Procurement Notes

Verify the specific suffix KR against official Analog Devices documentation to confirm package type and temperature grade. Ensure compatibility with existing board layouts and thermal requirements before procurement. Cross-reference with authorized distributors for current availability status.

Selection Notes

Select this component when precise RMS conversion is required for complex waveforms without external calibration. Consider the negative-going output characteristic relative to system ground references. Evaluate power supply constraints against the specified wide operating range for optimal noise performance.

Part Context

The AD737 series represents a family of precision analog converters designed for accurate signal processing. The AD737 specifically offers a negative output polarity, distinguishing it from the positive-output AD736 variant. Both devices share identical internal architecture and performance specifications regarding accuracy and bandwidth.

Replacement Considerations

The AD736 serves as a functional substitute with identical electrical characteristics but provides a positive-going output voltage instead of negative.