MODEL PTF Metal Film Resistors Industrial, Precision Low TC - Tight Tolerance FEATURES * Extremely low temperature coefficients of resistance * Very low noise and voltage coefficient * Wide precision resistance range in small package * 100% laser spiralled * Very good high frequency characteristics * Acceptance testing available * Can replace wirewound bobbins * Proprietary epoxy coating provides superior moisture protection MATERIAL SPECIFICATIONS STANDARD ELECTRICAL SPECIFICATIONS RESISTANCE RANGE (Grams) MAXIMUM WORKING VOLTAGE (Ohms) AVAILABLE TOLERANCE RANGE MAXIMUM WEIGHT MODEL + 85C RATING PTF-51 1/20 W .11 200 15 - 100k 1% to 0.02% PTF-56 1/8 W .35 300 15 - 500k 1% to 0.01% PTF-65 1/4 W .75 500 15 - 1M 1% to 0.05% Element: Precision deposited nickelchrome alloy with controlled annealing. Core: Fire-cleaned high purity ceramic. Encapsulant: Specially formulated epoxy compounds. Coated construction. Termination: Standard lead material is solder-coated copper. Solderable and weldable per MIL-STD-1276, Type C. DIMENSIONAL CONFIGURATIONS [Numbers in brackets indicate millimeters] C 1.50 .125 [38.1 3.18] A C Max. D MODEL A B (Max.) D PTF-51 .150 .020 [3.81 .508] .070 .010 [1.78 .254] .200 [5.08] .016 [.406] PTF-56 .250 + .031 - .046 [6.35 + .787 - 1.17] .091 .009 [2.31 .229] .300 [7.62] .025 [.635] PTF-65 .375 .062 [9.53 1.57] .145 .016 [3.68 .406] .475 [12.07] .025 [.635] B ENVIRONMENTAL PERFORMANCE TEST DESCRIPTION TEST SPECIFICATION MAXIMUM R (Typical Test Lots) Thermal Shock (- 55C to + 85C) MIL-STD-202, Method 107 .02% Short Time Overload MIL-R-10509, Para. 4.6.6 .01% Low Temperature Operation MIL-STD-55182, Methods 4.7.9 .02% Moisture MIL-R-202, Method 106 .08% Resistance to Soldering Heat MIL-STD-202, Methods 210 .02% Damp Heat IEC Publication #68-2-3 (56 days) .08% Life (1000 hours rated power @ + 85C) MIL-R-55182, Para. 4.7.17 .04% Dielectric Withstanding Voltage MIL-STD-202, Methods 301 & 105 .01% Vishay Dale 2300 Riverside Blvd., Norfolk, NE 68701-2242 * Phone (402) 371-0080 * Fax 402-644-4206 * Internet www.vishay.com Major Vishay Brands Dale * Draloric * Foil Resistors * Measurements Group * Roederstein * Sfernice * Sprague * Thin Film * Vitramon MODEL PTF TEMPERATURE COEFFICIENT OF RESISTANCE MATCHED SETS - NETWORKS Temperature coefficient (TC) of resistance is normally stated as the maximum amount of resistance change from the original + 25C value as the ambient temperature increases or decreases. This is most commonly expressed in parts per million per degree centigrade (PPM/C). Dale's(R) many years of experience in matching resistors for sets and networks, combined with the superb performance of the PTF product, provide the best and most economical solution to your precision resistor requirements. Why? Because most applications for precision resistors depend on two or more discretes having an initial tolerance ratio and a resistance tracking capability over temperature rather than each discrete resistor meeting the absolute requirements of the application. The resistance curve over the operating temperature range is usually a non-linear curve within predictable maximum limits. PTF resistors have a very uniform resistance temperature characteristic when measured over the operating range of - 20C to + 85C. The standard temperature coefficients available are T-10 = 15PPM/C, T-13 = 10PPM/C and T-16 = 5PPM/C. Some applications of the PTF require operation beyond the specifications of - 20C to + 85C. The change in temperature coefficient of resistance is very small (less than 0.05PPM/C) over the expanded temperature range of - 55C to + 150C. Therefore, when operating outside the range of - 20C to + 85C, the designer can plan for a worst case addition of 0.05PPM/C for each degree centigrade beyond either - 20C or + 85C as indicated in the graph. This applies to all three temperature coefficient codes. Cost savings approaching 50% can be realized when relatively tight matching requirements are specified while permitting the absolute parameters of the discrete resistors to have more relaxed specifications. Dale(R) application engineers are available to assist you in specifying your requirements in the most economical way possible. PTF resistors have an operating temperature range of - 55C to + 150C. They must be derated according to the curve below. 3 2 1 - 20C TO + 85C BASE TC LIMIT 0 - 50 - 40 - 30 - 20 EXPANDED OPERATING RANGE - 55C TO - 20C 90 T-10, T-13 or T-16 100 110 120 130 140 150 EXPANDED OPERATING RANGE + 85C TO + 150C % OF RATED POWER PPM/C ADDITION TO BASE TC IN THE EXPANDED PORTION OF THE TEMPERATURE RANGE DERATING 4 120 100 + 85C 80 60 40 20 0 30 50 70 90 110 130 150 AMBIENT TEMP. DEG. CENTIGRADE Example: Assume the operating characteristics demand a temperature range from - 55C to + 125C. This requires a 35C below - 20C and a 40C above + 85C. The extreme being 40C means that the worst case addition to the specified TC limit of 0.05PPM/C times 40C or 2PPM/C. Therefore, a T-16 which is characterized by a base TC limit of 5PPM/C over the temperature range of - 20C to + 85C will exhibit a maximum temperature coefficient of 7PPM/C over the expanded portion of the temperature range of - 55C to + 125C. PART MARKING -- Model -- Value -- Tolerance -- TC -- Date code HOW TO ORDER PTF 56 20K01 B T-13 MODEL SIZE VALUE TOLERANCE TEMPERATURE COEFFICIENT F = 1.0% T-10 = 0 15PPM/C T-13 = 0 10PPM/C T-16 = 0 5PPM/C DECIMAL LOCATOR/MULTIPLIER Code R K M Resistance = x1 = x 1000 = x 1,000,000 Examples: 50R 62R2 100R1 1K001 10K1 100K1 1M0 = = = = = = = 50 62.2 100.1 1001 10,100 100,100 1,000,000 D = 0.5% C = 0.25% B = 0.1% A = 0.05% BC = 0.02% BB = 0.01% Example: PTF-56, 20K01, B, T-13 = A precision thin film resistor, 1/8 watt with resistance of 20,010 ohms, tolerance of 0.1% and 0 10PPM/C TCR. Vishay Dale 2300 Riverside Blvd., Norfolk, NE 68701-2242 * Phone (402) 371-0080 * Fax 402-644-4206 * Internet www.vishay.com Major Vishay Brands Dale * Draloric * Foil Resistors * Measurements Group * Roederstein * Sfernice * Sprague * Thin Film * Vitramon