The AD637 series complete high accuracy RMS-to-DC Converter that computes the true RMS value of any complex waveform. It is a performance that is unprecedented in integrated circuit RMS-to-DC converters and comparable to discrete and modular techniques inaccuracy, bandwidth, and dynamic range. The AD637 computes the true root mean square, mean square or absolute value of any complex AC (AC plus DC) input waveform and gives an equivalent DC output voltage. The true RMS value of a waveform is more useful than an average rectified signal because it relates directly to the power of the signal. The RMS value of a statistical signal relates to the standard deviation of the signal. Superior crest factor compensation permits measurements of signals with crest factors of up to 10 with less than 1% additional error.

• High accuracy – 0.02% maximum Nonlinearity, 0 to 2Vrms input.
• High accuracy – 0.1% additional Error to crest factor of 3.
• Computes true RMS, square, mean square and absolute value.
• 60dB Output range.
• Chip select / power-down feature allows analogue three-state operation.
• Chip select / power-down feature allows quiescent current reduction from 2.2mA to 350µA.