Type USF Ultra-Stable Low TC Film Resistors 200 Series and 300 Series Page 1 of 2 Zero Nominal TC -- Maximum Absolute TC to 2 ppm/C, -40C to +85C ref. to +25C Absolute Tol. to 0.01%, Resistance Range 50 Ohm to 25 Megohm, Voltage Ratings up to 2500 Volts The USF Ultra-Stable Low TC Ultra-Precision Film Resistors were developed to meet the requirements for increasing performance for resistors in high performance analog electronics. Utilizing Caddock proprietary resistance film systems, the Type USF resistors provide the Lowest TC with the Widest Resistance Range and the Highest Voltage Ratings available in the industry. * Resistance Range 50 ohm to 25 Megohm. * Temperature Coefficient -40C to +85C, referenced to +25C 200 Series -- ZERO Nominal TC -- Maximum Absolute TC 2 ppm/C 300 Series -- ZERO Nominal TC -- Maximum Absolute TC 5 ppm/C * Tolerance: 0.01% or 0.10%. * Specific standard resistance values are available that are most commonly required in high accuracy analog design. These values were selected and optimized for produceability and performance. Type USF 200 Series Ultra-Stable Resistors * 300 Series "matched pairs" are available with ratio TC as tight as * 0.5 ppm/C. Contact Applications Engineering. * Ceramic package provides cool operation. Type USF Ultra-Stable Resistors are offered in standard resistance values that are most commonly used in precision analog design. These standard resistance values can be used in precise amplifier gain setting, precise resistor bridge circuits, precise transducer sense circuits, and precise voltage dividers with up to 2500 volt input voltage. Extremely Low Power Coefficient (Wattage Coefficient): Type USF resistors are constructed with an aluminum oxide ceramic sandwich which provides great thermal conductivity. The ceramic sandwich package very effectively minimizes the power coefficient drift. Power coefficient is the resistance drift due to temperature rise in the element caused by the power (wattage) dissipation in the resistor where the selfheating temperature rise of the resistor element results in TC drift (temp. rise in C, times the temperature coefficient of the resistor). In the USF package, heat is pulled away from the resistance material efficiently by this ceramic sandwich package construction. Plastic molded Low TC foil resistors cannot provide this outstanding benefit since the plastic impedes the flow of heat, causing greater temperature rise at the resistor element and greater self-heating related resistance drift due to power dissipation. The USF 200 Series resistors provide a new level of performance with near ZERO TC, very low power coefficient, wide resistance range, and higher voltage ratings than is offered by other resistor technologies. * Constructed with two selected USF 300 Series Resistors bonded back to back to achieve outstanding low Absolute Temperature Coefficient performance. The resistors are to be connected in parallel on the circuit board. ZERO Nominal TC -- Max. Absolute TC: 2 ppm/C, -40C to +85C, referenced to +25C Type USF 300 Series Ultra-Stable Resistors * ZERO Nominal TC -- Max. Absolute TC: 5 ppm/C, -40C to +85C, referenced to +25C Model Number @ +85C Wattage Maximum Continuous Oper. Voltage Min. Max. Temperature Coefficient Fig. USF240 0.33 300 50 10 Meg 2 ppm/C 1 USF270 0.75 1,400 990 K 5 Meg 2 ppm/C 1 USF271 0.75 2,500 9.9 Meg 10 Meg 2 ppm/C 1 1.500 .020 (38.10 .51) .500 .020 (12.70 .51) USF340 0.33 300 50 20 Meg 5 ppm/C 2 .750 .020 (19.05 .51) USF370 0.75 1,400 990 K 10 Meg 5 ppm/C 2 .375 .020 (9.53 .51) .500 .020 (12.70 .51) USF371 0.75 2,500 19.8 Meg 25 Meg 5 ppm/C 2 Resistance ELECTRONICS, INC. e-mail: caddock@caddock.com * web: www.caddock.com For Caddock Distributors listed by country see caddock.com/contact/dist.html (c) 2003-2017 Caddock Electronics, Inc. A .750 .020 (19.05 .51) 1.500 .020 (38.10 .51) 1.500 .020 (38.10 .51) 1.500 .020 (38.10 .51) Dimensions inches (mm) B .375 .020 (9.53 .51) .500 .020 (12.70 .51) .500 .020 (12.70 .51) C .425 Max. (10.8 Max.) .550 Max. (13.97 Max.) .550 Max. (13.97 Max.) .395 Max. (10.03 Max.) .520 Max. (13.21 Max.) .520 Max. (13.21 Max.) D .600 .020 (15.24 .51) 1.350 .020 (34.29 .51) 1.350 .020 (34.29 .51) .600 .020 (15.24 .51) 1.350 .020 (34.29 .51) 1.350 .020 (34.29 .51) Sales and Applications Engineering 17271 North Umpqua Hwy. Roseburg, Oregon 97470-9422 Phone: (541) 496-0700 Fax: (541) 496-0408 28_IL134.01717 Type USF Ultra-Stable Low TC Film Resistors 200 Series and 300 Series Standard Resistance Values: Fig. 1 USF 200 Series USF240 Standard Resistance Values: Absolute Tolerance: 0.01% or 0.10%, Absolute TC: 2ppm/C 50.0 100 200 250 350 500 900 1.00 K 2.00 K 2.50 K 5.00 K 9.00 K 10.0 K 20.0 K 25.0 K 50.0 K 90.0 K 99.0 K 100 K 200 K 250 K 500 K 1.00 Meg 2.00 Meg USF270 Standard Resistance Values: 2.50 Meg 10.0 Meg 5.00 Meg 9.90 Meg 9.99 Meg Top View Front View 1.00 Meg 2.00 Meg 5.00 Meg USF271 Standard Resistance Values: 9.90 Meg 9.99 Meg 10.0 Meg B CADDOCK USF24004 18 .032 DIA. (.81 DIA.) Absolute Tolerance: 0.01% or 0.10%, Absolute TC: 2ppm/C .50 .125 (12.70 3.18) USF340 Standard Resistance Values: Absolute Tolerance: 0.01% or 0.10%, Absolute TC: 5ppm/C 50.0 100 200 350 400 500 700 1.00 K 1.80 K 2.00 K 4.00 K 5.00 K 10.0 K 18.0 K 20.0 K 40.0 K 50.0 K 90.0 K 99.0 K 100 K 180 K 198 K 200 K 400 K 500 K 990 K 999 K 1.00 Meg USF370 Standard Resistance Values: 2.00 Meg 4.00 Meg 5.00 Meg 9.90 Meg 9.99 Meg 10.0 Meg 19.8 Meg 19.98 Meg 20.0 Meg Absolute Tolerance: 0.01% or 0.10%, Absolute TC: 5ppm/C 990 K 1.98 Meg 4.00 Meg 9.90 Meg 10.0 Meg 1.00 Meg 2.00 Meg 5.00 Meg 9.99 Meg Dimensions in inches and (millimeters) .160 .030 (4.06 .76) A Absolute Tolerance: 0.01% or 0.10%, Absolute TC: 2ppm/C 990 K Page 2 of 2 D C (seated height) Side View .200 .020 (5.08 .51) USF 200 Series Circuit Board Connection Note: The Type USF 200 Series Resistor must have the two "bonded" resistors in the package connected in parallel on the circuit board as shown. This parallel connection of the two resistors achieves the specified resistance with the specified performance. USF371 Standard Resistance Values: Circuit Board Trace Absolute Tolerance: 0.01% or 0.10%, Absolute TC: 5ppm/C Circuit Board Trace 19.8 Meg 19.98 Meg 20.0 Meg 25.0 Meg Fig. 2 USF 300 Series Specifications: Resistance Tolerance: 0.01% or 0.10 measured at +23C 2C. Absolute Temperature Coefficient: TC referenced to +25C, R taken at -40C and +85C. Load Life Stability: 2,000 hours at +85C at rated voltage, not to exceed rated power, R (+0.015 0.015)% max. 10,000 hours at +85C at rated voltage, not to exceed rated power, R (+0.030 0.030)% max. Thermal Shock: Mil-Std-202 Method 107 condition A, except min. temp. is -40C, R 0.01% maximum. Voltage Coefficient: USF270 at 5 Meg, and USF271, USF370, USF371 at resistances of 9 Meg or greater, 0.02 ppm/volt maximum. Shelf Life Stability: Typical +(20ppm 20ppm)/yr. after 1 year. Extended shelf life (ten years) 10ppm/year maximum. Operating Temperature: -40C to +85C. Leadwire: Solder Coated Copper. Ordering Information USF200 Series: USF240 - 10.0 Meg - 0.01% - 2 ppm/C Model Number Resistor Value Tolerance (0.01% or 0.10%) Ordering Information USF300 Series: USF370 - 990K - 0.10% - 5 ppm/C Model Number Resistor Value Tolerance (0.01% or 0.10%) A Front View .032 DIA. (.81 DIA.) .50 .125 (12.70 3.18) D C (seated height) Side View Dimensions in inches and (millimeters) Custom USF 200 Series and 300 Series Resistors: USF 200 Series and 300 Series Resistors are available, for high quantity applications, with custom performance: * In the 200 Series, Absolute TC to as tight as 1ppm/C is available for certain resistances. * Matched Ratio TC to as tight as 0.5ppm/C for equal resistances. * Matched Ratio TC can be provided in the 200 Series style "bonded" Resistor pairs. Other Low TC Resistor Products from Caddock: * * * * * * * Type TF Low TC Ultra-Precision Film Resistors (1K to 125Meg) Type TN Lab Grade Low TC Precision Film Resistors Type TK Low TC Precision Radial-Lead Film Resistors Type TG Low TC Precision High Voltage Resistors (up to 30KV) T912 and T914 Low TC Ultra-Precision Resistor Networks Type USVD Ultra-Stable Voltage Dividers (up to 2500V) Type THV Precision High Voltage Dividers (up to 20KV) ELECTRONICS, INC. e-mail: caddock@caddock.com * web: www.caddock.com For Caddock Distributors listed by country see caddock.com/contact/dist.html (c) 2003-2017 Caddock Electronics, Inc. B CADDOCK USF34004 12 .075 .020 (1.91 .51) Sales and Applications Engineering 17271 North Umpqua Hwy. Roseburg, Oregon 97470-9422 Phone: (541) 496-0700 Fax: (541) 496-0408 28_IL134.01717