Saturday, April 01, 2017

AD8436 - Low Cost RMS to DC Convertor

This chip from Analog Devices  computes a precise dc equivalent of the rms value ac waveforms, including complex patterns such as those generated by switchmode power supplies and triacs.

AD8436 - Low Cost RMS to DC Convertor

There is an evaluation board available to study its performance.

AD8436 - Low Cost RMS to DC Convertor

Delivers true RMS or average rectified value of an AC input and Fast is settling at all input levels.It is an Accurate conversion with crest factors up to 10.

AD8436 - Low Cost RMS to DC Convertor

Typical application for frequencies as low as power line, and above. The recommended averaging, crest factor and LPF capacitor values are 10 μF, 0.1 μF and 3.3 μF.

Other Features
  • Accuracy: ±10 µV ± 0.5% of reading 
  • 100 µV rms to 3 V rms (8.5 V p-p) full-scale input
  • 1 MHz for -3 dB (300 mV) 
  • 65 kHz for additional 1% error 
  • Zero converter dc output offset 
  • Low power: 300 µA typical at ±2.4 V