LTC6990 ELECTRICAL CHARACTERISTICSNote 11: Long-term drift of silicon oscillators is primarily due to the the square root and multiply by the typical drift number. For instance, a movement of ions and impurities within the silicon and is tested at 30°C year is 8.77kHr and would yield a drift of 266ppm at 90ppm/√kHr. Drift under otherwise nominal operating conditions. Long-term drift is specified without power applied to the device may be approximated as 1/10th of the as ppm/√kHr due to the typically nonlinear nature of the drift. To calculate drift with power, or 9ppm/√kHr for a 90ppm/√kHr device. drift for a set time period, translate that time into thousands of hours, take TYPICAL PERFORMANCE CHARACTERISTICS V+ = 3.3V, unless otherwise noted.Frequency ErrorFrequency Error vs RSETvs Supply VoltageFrequency Error vs Temperature 4 0.5 1.5 TA = 25°C TA = 25°C V+ = 3.3V 3 GUARANTEED MAX 0.4 DIVCODE = 4 OVER TEMPERATURE 0.3 1.0 2 0.2 RSET = 800k 0.5 1 TYPICAL MAX 0.1 RSET = 50k 0 90% OF UNITS 0 0.0 RSET = 200k RSET = 800k –1 TYPICAL MIN –0.1 ERROR (%) –0.2 –0.5 R FREQUENCY ERROR (%) –2 FREQUENCY ERROR (%) SET = 50k RSET = 267k GUARANTEED MIN –0.3 –1.0 –3 OVER TEMPERATURE –0.4 –4 –0.5 –1.5 10 100 1000 2 3 4 5 6 –50 –25 0 25 50 75 100 125 RSET (kΩ) SUPPLY VOLTAGE (V) TEMPERATURE (°C) 6990 G01 6990 G02 6990 G03 VSET vs ISETVSET vs Supply VoltageVSET vs Temperature 1.003 1.003 1.020 V+ = 3.3V RSET = 200k RSET = 200k TA = 25°C TA = 25°C 1.015 3 TYPICAL PARTS 1.010 1.002 1.002 1.005 (V) (V) (V) 1.000 V SET V SET V SET 0.995 1.001 1.001 0.990 0.985 1.000 1.000 0.980 0 10 20 30 40 2 3 4 5 6 –50 –25 0 25 50 75 100 125 ISET (µA) SUPPLY VOLTAGE (V) TEMPERATURE (°C) 6990 G04 6990 G05 6990 G06 6990fc For more information www.linear.com/LTC6990 5 Document Outline Features Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Package Description Revision History Related Parts