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RMS-to-DC converter IC

Wide dynamic range to accurately measure extremely low signal levels with no drop in settling time.

Analog Devices’ AD8436 precision monolithic true RMS-to-DC converter has 100 µV to 3V of usable dynamic range and features AC conversion accuracy to better than ± 0.5%. Uniform settling for widely variant input values enables consistent conversion rates with results displayed promptly for near-zero and high-level AC inputs. The AD8436 is, ADI says, immune to temperature, crest factor and supply voltage variations. Zero DC offset voltages at the converter output simplify calibration. The part occupies a 4 x 4 mm package, includes FET input and precision DC buffer amplifiers and consumes 300 µA.
Use it, ADI suggests, in remote, portable battery-powered instrumentation, energy and automotive applications where limited board space and outdoor environments are considerations.
You can update your knowledge of the relevant measurement techniques with Analog’s downloadable RMS-to-DC Conversion Application Guide; you can use these RMS-to-DC converters in applications where precise, low power measurement of AC/DC signals is the prime objective. The AD8436 system-on-a-chip design computes the precise DC equivalent of the RMS value and provides a level of linearity and accuracy across the entire input range that enables you to design systems with 90 dB of dynamic range.
The AD8436 extends the crest-factor to 10 – approximately double the current industry-standard digital solution – with minimal loss of accuracy. Input frequency range is 65 kHz for additional 1% error; accuracy is ±10 μV ± 0.5 percent of reading max. The device is laser trimmed and characterised at 300-mV RMS input and comes with dual and single power supplies. The AD8436 is the first RMS-to-DC converter specified to operate in the extended industrial temperature range of -40°C to 125°C (A-suffix device). It is also available in a 0°C to 70°C temperature range version (J-suffix); the p[arts cost $4.95 or $2.95, respectively (1000).