LTC1966 - Precision Micropower ΔΣ RMS-to-DC Converter

Features

  • Simple to Use, Requires One Capacitor
  • True RMS DC Conversion Using ∆Σ Technology
  • High Accuracy:
    0.1% Gain Accuracy from 50Hz to 1kHz
    0.25% Total Error from 50Hz to 1kHz
  • High Linearity:
    0.02% Linearity Allows Simple System Calibration
  • Low Supply Current:
    155μA Typ, 170μA Max
  • Ultralow Shutdown Current:
    0.1μA
  • Constant Bandwidth:
    Independent of Input Voltage
    800kHz –3dB, 6kHz ±1%
  • Flexible Supplies:
    2.7V to 5.5V Single Supply
    Up to ±5.5V Dual Supply
  • 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
  • Wide Temperature Range:
    –55°C to 125°C
  • Small Size:
    Space Saving 8-Pin MSOP Package
Designed for Automotive and Transportation Applications
AEC-Q100 generic family data available for specific packages


Typical Application

LTC1966 Typical Application
LTC1966 Typical Application

Description

The LTC®1966 is a true RMS-to-DC converter that utilizes an innovative patented ∆Σ computational technique. The internal delta sigma circuitry of the LTC1966 makes it simpler to use, more accurate, lower power and dramatically more flexible than conventional log antilog RMS-to-DC converters.

The LTC1966 accepts single-ended or differential input signals (for EMI/RFI rejection) and supports crest factors up to 4. Common mode input range is rail-to-rail. Differential input range is 1VPEAK, and offers unprecedented linearity. Unlike previously available RMS-to-DC converters, the superior linearity of the LTC1966 allows hassle free system calibration at any input voltage.

The LTC1966 also has a rail-to-rail output with a separate output reference pin providing flexible level shifting. The LTC1966 operates on a single power supply from 2.7V to 5.5V or dual supplies up to ±5.5V. A low power shutdown mode reduces supply current to 0.5μA.

The LTC1966 is insensitive to PC board soldering and stresses, as well as operating temperature. The LTC1966 is packaged in the space saving MSOP package which is ideal for portable applications.

Packaging

CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
Drawing
RoHS
LTC1966CMS8#PBF MS-8 MS8 C 05-08-1660 Yes
LTC1966CMS8#TRPBF MS-8 MS8 C 05-08-1660 Yes
LTC1966HMS8#PBF MS-8 MS8 H 05-08-1660 Yes
LTC1966HMS8#TRPBF MS-8 MS8 H 05-08-1660 Yes
LTC1966IMS8#PBF MS-8 MS8 I 05-08-1660 Yes
LTC1966IMS8#TRPBF MS-8 MS8 I 05-08-1660 Yes
LTC1966MPMS8#PBF MS-8 MS8 MP 05-08-1660 Yes
LTC1966MPMS8#TRPBF MS-8 MS8 MP 05-08-1660 Yes


LTC1966 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LTC1966CMS8#PBF MS-8 C $3.90 $2.95 Yes
LTC1966CMS8#TRPBF MS-8 C $3.01 Yes
LTC1966HMS8#PBF MS-8 H $9.68 $6.95 Yes
LTC1966HMS8#TRPBF MS-8 H $9.74 $7.01 Yes
LTC1966IMS8#PBF MS-8 I $6.60 $4.95 Yes
LTC1966IMS8#TRPBF MS-8 I $5.01 Yes
LTC1966MPMS8#PBF MS-8 MP $12.48 $8.95 Yes
LTC1966MPMS8#TRPBF MS-8 MP $12.54 $9.01 Yes
Buy NowRequest Samples
* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Part Number Description Price Documentation
DC427B-A LTC1966CMS8 | RMS to DC Converter $50.00
Buy Now
Click here to view our complete list of demo boards

Designed for Automotive and Transportation Applications

Please contact your local sales representative for more information regarding reliability reports and AEC-Q100 data or to inquire about parts that are not included. For more information, view our Automotive and Transportation page

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LTC1966HMS8#PBF MS-8 H $9.68 $6.95 Yes
LTC1966HMS8#TRPBF MS-8 H $9.74 $7.01 Yes
LTC1966IMS8#PBF MS-8 I $6.60 $4.95 Yes
LTC1966IMS8#TRPBF MS-8 I $5.01 Yes
LTC1966MPMS8#PBF MS-8 MP $12.48 $8.95 Yes
LTC1966MPMS8#TRPBF MS-8 MP $12.54 $9.01 Yes
Buy NowRequest Samples
* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Applications

  • True RMS Digital Multimeters and Panel Meters
  • True RMS AC + DC Measurements

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Design Tools

LTspice

LTspice® software is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice

To launch a ready to run LTspice demonstration circuit for this part:

  • Step 1: If you have not installed LTspice on this computer, download and install LTspice
  • Step 2: Once LTspice is installed, click on the link(s) below to launch the simulation
  • Step 3: If LTspice does not automatically open after clicking the link above, you can instead run the simulation by right clicking on the link and selecting "Save Target As." After saving the file to your computer, start LTspice and open the demonstration circuit by selecting 'Open' from the 'File' menu

To explore other ready to run LTspice demonstration circuits, please visit our Demo Circuits Collection.

Models for the following parts are available in LTspice:
LTC1966

Technical Support