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

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