Integrated Circuits

IC chips and Discrete Devices. Silicon, Germanium and Gallium Arsenide products. Diodes, Transistors and Zeners. Part of delabs Technologies

Search This Blog

Thursday, August 10, 2017

Precision RMS Value of AC Waveform - LTC1968

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

Linear Technology - RMS-DC Conversion

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.

Precision RMS Value of AC Waveform - LTC1968

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.

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