LTC1966 Precision Micropower RMS-to-DC Converter Fea T Descrip T n Simple to Use, Requires One Capacitor The LTC 1966 is a true RMS-to-DC converter that utilizes n True RMS DC Conversion Using DS Technology an innovative patented DS computational technique. The n High Accuracy: internal delta sigma circuitry of the LTC1966 makes it sim- 0.1% Gain Accuracy from 50Hz to 1kHz pler to use, more accurate, lower power and dramatically more flexible than conventional log antilog RMS-to-DC 0.25% Total Error from 50Hz to 1kHz n converters. High Linearity: 0.02% Linearity Allows Simple System Calibration The LTC1966 accepts single-ended or differential input n Low Supply Current: signals (for EMI/RFI rejection) and supports crest factors up 155A Typ, 170A Max to 4. Common mode input range is rail-to-rail. Differential n Ultralow Shutdown Current: input range is 1V , and offers unprecedented linearity. PEAK 0.1A Unlike previously available RMS-to-DC converters, the n Constant Bandwidth: superior linearity of the LTC1966 allows hassle free system Independent of Input Voltage calibration at any input voltage. 800kHz 3dB, 6kHz 1% The LTC1966 also has a rail-to-rail output with a separate n Flexible Supplies: output reference pin providing flexible level shifting. The 2.7V to 5.5V Single Supply LTC1966 operates on a single power supply from 2.7V to Up to 5.5V Dual Supply 5.5V or dual supplies up to 5.5V. A low power shutdown n Flexible Inputs: mode reduces supply current to 0.5A. Differential or Single-Ended The LTC1966 is insensitive to PC board soldering and Rail-to-Rail Common Mode Voltage Range stresses, as well as operating temperature. The LTC1966 Up to 1V Differential Voltage PEAK is packaged in the space saving MSOP package which is n Flexible Output: ideal for portable applications. Rail-to-Rail Output Separate Output Reference Pin Allows Level Shifting a T n Wide Temperature Range: n 55C to 125C True RMS Digital Multimeters and Panel Meters n n Small Size: True RMS AC + DC Measurements Space Saving 8-Pin MSOP Package L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and No Latency DS is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 6359576, 6362677, 6516291 and 6651036. Quantum Leap in Linearity Performance Typical a T 0.2 LTC1966, Single Supply RMS-to-DC Converter 0 2.7V TO 5.5V 0.2 V DD 0.4 IN1 OUTPUT DIFFERENTIAL C + AVE LTC1966 V OUT 1F 0.6 INPUT CONVENTIONAL IN2 OUT RTN LOG/ANTILOG 1966 TA01 EN V GND SS 0.1F 0.8 OPT. AC COUPLING 60Hz SINEWAVES 1.0 0 50 100 150 200 250 300 350 400 450 500 V (mV AC ) IN RMS 1966 TA01b 1966fb 1 LINEARITY ERROR (V mV DC V mV AC ) OUT IN RMS ion pplica ions pplica ion uresLTC1966 a Te Maxi Mu M r a T p in c F T (Note 1) Supply Voltage V to GND ............................................. 0.3V to 7V DD V to V ............................................ 0.3V to 12V DD SS V to GND ............................................. 7V to 0.3V SS TOP VIEW Input Currents (Note 2) ...................................... 10mA GND 1 8 ENABLE IN1 2 7 V Output Current (Note 3) ..................................... 10mA DD IN2 3 6 OUT RTN ENABLE Voltage ....................... V 0.3V to V + 12V 5 V SS SS V 4 SS OUT OUT RTN Voltage ............................... V 0.3V to V MS8 PACKAGE SS DD 8-LEAD PLASTIC MSOP Operating Temperature Range (Note 4) T = 150C, = 220C/W JMAX JA LTC1966C/LTC1966I ............................40C to 85C LTC1966H .......................................... 40C to 125C LTC1966MP ....................................... 55C to 125C Specified Temperature Range (Note 5) LTC1966C/LTC1966I ............................40C to 85C LTC1966H .......................................... 40C to 125C LTC1966MP ....................................... 55C to 125C Maximum Junction Temperature ......................... 150C Storage Temperature Range ................. 65C to 150C Lead Temperature (Soldering, 10 sec) .................. 300C o r Der i n F Ma T LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC1966CMS8 PBF LTC1966CMS8 TRPBF LTTG 8-Lead Plastic MSOP 0C to 70C LTC1966IMS8 PBF LTC1966IMS8 TRPBF LTTH 8-Lead Plastic MSOP 40C to 85C LTC1966HMS8 PBF LTC1966HMS8 TRPBF LTTG 8-Lead Plastic MSOP 40C to 125C LTC1966MPMS8 PBF LTC1966MPMS8 TRPBF LTTG 8-Lead Plastic MSOP 55C to 125C Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. For more information on lead free part marking, go to: