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.

The LTC1968 operates with single-ended or differential input signals and accurately supports crest factors up to 4. Common mode input range is rail-to-rail. Differential input range is 1VPEAK, and offers unprecedented linearity. The LTC1968 allows hassle-free system calibration at any input voltage.

The LTC1968 has a rail-to-rail output with a separate output reference pin providing flexible level shifting; it operates on a single power supply from 4.5V to 5.5V. A low power shutdown mode reduces supply current to 0.1µA.

The LTC1968 is packaged in the space-saving MSOP package, which is ideal for portable applications.

Applications

* True RMS Digital Multimeters and Panel Meters

* True RMS AC + DC Measurements

* 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

* No-Hassle Simplicity:

* True RMS-DC Conversion with Only One External Capacitor

* Delta Sigma Conversion Technology

* Ultralow Shutdown Current:

* 0.1µA

* Flexible Inputs:

* Differential or Single Ended

* Rail-to-Rail Common Mode Voltage Range

* Up to 1VPEAK Differential Voltage

* Flexible Output:

* Rail-to-Rail Output

* Separate Output Reference Pin Allows Level Shifting

* Small Size:

* Space Saving 8-Pin MSOP Package