AD637BQ

Overview

The AD637BQ is a high-precision monolithic true RMS-to-DC converter manufactured by Analog Devices Inc. It calculates the true root-mean-square value of complex waveforms with a maximum nonlinearity error of 0.02%. The device features a wide bandwidth of 8 MHz at a 2 Vrms input and supports a peak factor up to 10 with less than 1% additional error. It operates on dual supplies ranging from ±3V to ±18V, drawing 2.2 mA typically, which can be reduced to 350 μA via the chip select pin. The component is housed in a 14-pin CERDIP package.

Feature Summary

• Provides true RMS conversion for arbitrary waveforms including DC and AC signals
• Features a dedicated chip select pin for power reduction and analog tri-state output
• Includes an auxiliary dB output pin for direct logarithmic signal measurement
• Integrates internal buffer amplifiers for high input impedance and low output impedance

Applications

• Precision power measurement systems
• Industrial process control instrumentation
• Audio equipment testing and analysis
• Data acquisition systems requiring accurate waveform characterization

Procurement Notes

Verify the specific suffix BQ corresponds to the required temperature range and packaging configuration against the official datasheet. Confirm that the 14-pin CERDIP package meets the mechanical constraints of the target PCB layout. Ensure supply voltage polarity matches the ±3V to ±18V requirement to prevent device damage during integration.

Selection Notes

Select this component when high accuracy and wide bandwidth are critical for non-sinusoidal signal analysis. The integrated chip select feature makes it suitable for battery-powered or low-power applications where standby current must be minimized. Consider the CERDIP package if through-hole mounting and hermetic sealing are necessary for the environment.

Part Context

The AD637 series represents a class of precision analog signal processing components designed for accurate energy calculation. Unlike average-responding meters, these converters perform mathematical squaring, averaging, and square-rooting operations internally. This ensures accurate readings regardless of waveform shape, distinguishing them from simpler rectifier-based measurement circuits.

Replacement Considerations

Public confirmed substitute part numbers: None identified in provided documentation.