Showing posts with label True-RMS-IC. Show all posts
Showing posts with label True-RMS-IC. Show all posts

Saturday, October 24, 2015

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.

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

Friday, December 30, 2011

AD636 - True RMS to DC Converter

Working on low signals in the range of 0 mV to 200 mV rms, AD636 makes a precision AC to DC signal conditioner for Instrumentation. DMM, Data Loggers and Process Indicators can use this.

AD636 - True RMS to DC Converter

AD636 Low Level True RMS-to-DC Converter

Some Features and Specs

  • Laser-trimmed to high accuracy
  • 0.5% maximum error (AD636K)
  • Computes rms of ac and dc signals
  • 1 MHz, −3 dB bandwidth: V rms > 100 mV
  • Signal crest factor of 6 for 0.5% error
  • Low power: 800 μA quiescent current

From Analog Devices

Thursday, December 29, 2011

Precision RMS Value of AC Waveform - LTC1968

"RMS to DC conversion is the truest way to measure the energy contained in an AC waveform."

The accurate measurement of AC for a wide variety of waveforms and noise is difficult. When we make solar systems and inverters, the AC outputs are seldom sinusoidal. The easy method is to use a Precision rectifier/filter, get the average voltage and a RMS calibration/scaling is done for sine is by tweaking a trimpot. This will not show the right values for other waveforms. The other way was, analog computing, with many opamps and a matched pair of transistors; like multipliers and log amps, very cumbersome for manufacturing and testing.

These single chip solutions like LTC1968 - Precision Wide Bandwidth, RMS-to-DC Converter make it easy to implement an AC Measurement in your embedded, PLC or PC based solution.

Learn more about RMS here Make Better RMS Measurements with Your DMM

LTC1968 - Precision Wide Bandwidth, RMS-to-DC Converter

LTC1968 - Precision Wide Bandwidth, RMS-to-DC Converter

The LTC1968 is a true RMS-to-DC converter that uses an innovative delta-sigma computational technique. The benefits of the LTC1968 proprietary architecture, when compared to conventional log-antilog RMS-to-DC converters, are higher linearity and accuracy, bandwidth independent of amplitude and improved temperature behavior.

High Linearity: 0.02% Linearity Allows Simple System Calibration

Wide Input Bandwidth:

  • Bandwidth to 1% Additional Gain Error: 500kHz
  • Bandwidth to 0.1% Additional Gain Error: 150kHz
  • 3dB Bandwidth Independent of Input Voltage Amplitude

Linear Technology - RMS-DC Conversion