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 Max. Abs. TC 5 ppm/C or 10 ppm/C Tolerance: 0.01% or 0.1%. 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 Matched Pairs of USF 300 Series are available with ratio TC as tight as Constructed with two selected USF 300 Series 0.5 ppm/C. Contact Applications Engineering. Resistors bonded back to back to achieve outstanding low Absolute Temperature Coefficient Ceramic package provides cool operation. performance. The resistors are to be connected in Type USF Ultra-Stable Resistors are offered in standard resistance values parallel on the circuit board. that are most commonly used in precision analog design. These standard ZERO Nominal TC Max. Absolute TC: 2 ppm/C, resistance values can be used in precise amplifier gain setting, precise -40C to +85C, referenced to +25C 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 that 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 self- heating 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 Type USF 300 Series Ultra-Stable Resistors ZERO TC, very low power coefficient, wide resistance range, and higher ZERO Nominal TC Max. Absolute TC: 5 ppm/C voltage ratings than is offered by other resistor technologies. or 10 ppm/C, -40C to +85C, referenced to +25C Maximum Resistance Dimensions inches (mm) Wattage Temperature Fig. Model Number Continuous Tolerance +85C Coefficient A D Min. Max. B C Oper. Voltage .750 .020 .375 .020 .425 Max600 .020 USF240 0.33 0.01% or 0.1% 2 ppm/C 1 300 50 10 Meg (19.05 .51) (9.53 .51) (10.8 Max.) (15.24 .51) 1.500 .020 .500 .020 1.350 .020 .550 Max. USF270 0.75 1,400 0.01% or 0.1% 2 ppm/C 1 990 K 5 Meg (38.10 .51) (12.70 .51) (34.29 .51) (13.97 Max.) 1.500 .020 .500 .020 .550 Max. 1.350 .020 USF271 0.75 0.01% or 0.1% 2 ppm/C 1 2,500 9.9 Meg 10 Meg (38.10 .51) (12.70 .51) (13.97 Max.) (34.29 .51) .600 .020 5 ppm/ C or .750 .020 .375 .020 .395 Max. USF340 0.33 2 300 50 20 Meg 0.01% or 0.1% (15.24 .51) 10 ppmC (19.05 .51) (9.53 .51) (10.03 Max.) .500 .020 1.350 .020 5 ppm/ C or 1.500 .020 .520 Max. USF370 0.75 2 1,400 990 K 10 Meg 0.01% or 0.1% (12.70 .51) (34.29 .51) 10 ppmC (38.10 .51) (13.21 Max.) 5 ppm/ C or 1.500 .020 .500 .020 .520 Max. 1.350 .020 USF371 0.01% or 0.1% 0.75 2,500 19.8 Meg 25 Meg 2 10 ppmC (38.10 .51) (12.70 .51) (13.21 Max.) (34.29 .51) Sales and Applications Engineering 17271 North Umpqua Hwy. ELECTRONICS, INC. Roseburg, Oregon 97470-9422 e-mail: caddock caddock.com web: www.caddock.com Phone: (541) 496-0700 For Caddock Distributors listed by country see caddock.com/contact/dist.html Fax: (541) 496-0408 2019 Caddock Electronics, Inc. 28 IL134.0819Type USF Ultra-Stable Low TC Film Resistors 200 Series and 300 Series Page 2 of 2 Standard Resistance Values: Fig. 1 Dimensions in inches USF240 Standard Resistance Values: and (millimeters) USF 200 Series Absolute Tolerance: 0.01% or 0.1%, Absolute TC: 2 ppm/C 50.0 350 2.00 K 10.0 K 90.0 K 250 K 2.50 Meg 10.0 Meg Top View 100 500 2.50 K 20.0 K 99.0 K 500 K 5.00 Meg .155 .025 200 900 5.00 K 25.0 K 100 K 1.00 Meg 9.90 Meg A (3.94 .64) 250 1.00 K 9.00 K 50.0 K 200 K 2.00 Meg 9.99 Meg USF270 Standard Resistance Values: Front View Absolute Tolerance: 0.01% or 0.1%, Absolute TC: 2 ppm/C C CADDOCK B USF240 990 K 1.00 Meg 2.00 Meg 5.00 Meg 1921 (seated height) USF271 Standard Resistance Values: .032 DIA50 .125 Absolute Tolerance: 0.01% or 0.1%, Absolute TC: 2 ppm/C (.81 DIA.) (12.70 3.18) 9.90 Meg 9.99 Meg 10.0 Meg Side View USF340 Standard Resistance Values: Absolute Tolerance: 0.01% or 0.1%, Absolute TC: 5 ppm/C or 10 ppm/C D .200 .020 50.0 400 1.80 K 10.0 K 50.0 K 180 K 500 K 2.00 Meg 9.99 Meg (5.08 .51) 100 500 2.00 K 18.0 K 90.0 K 198 K 990 K 4.00 Meg 10.0 Meg 200 700 4.00 K 20.0 K 99.0 K 200 K 999 K 5.00 Meg 19.8 Meg 350 1.00 K 5.00 K 40.0 K 100 K 400 K 1.00 Meg 9.90 Meg 19.98 Meg USF 200 Series Circuit Board Connection Note: The Type USF 200 20.0 Meg Series Resistor must have the two bonded resistors in the package connected USF370 Standard Resistance Values: in parallel on the circuit board as shown. This parallel connection of the two Absolute Tolerance: 0.01% or 0.1%, Absolute TC: 5 ppm/C or 10 ppm/C resistors achieves the specified resistance with the specified performance. 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 USF371 Standard Resistance Values: Circuit Board Trace Circuit Board Trace Absolute Tolerance: 0.01% or 0.1%, Absolute TC: 5 ppm/C or 10 ppm/C 19.8 Meg 19.98 Meg 20.0 Meg 25.0 Meg Specifications: Fig. 2 USF 300 Series Resistance Tolerance: 0.01% or 0.1% measured at +23C 2C075 .020 Absolute Temperature Coefficient: TC referenced to +25C, (1.91 .51) A R taken at -40C and +85C. Load Life Stability: 2,000 hours at +85C at rated voltage, not to Front View C exceed rated power, R (+0.015 0.015)% max. CADDOCK B USF340 (seated height) 1920 10,000 hours at +85C at rated voltage, not to exceed rated power, R (+0.030 0.030)% max032 DIA50 .125 (.81 DIA.) Thermal Shock: Mil-Std-202 Method 107 condition A, except min. (12.70 3.18) temp. is -40C, R 0.01% maximum. Side View Voltage Coefficient: USF270 at 5 Meg, and USF271, USF370, D Dimensions in inches USF371 at resistances of 9 Meg or greater, 0.02 ppm/volt and (millimeters) maximum. Shelf Life Stability: Typical +(20ppm20ppm)/yr. after 1 year. Extended shelf life (ten years) 10 ppm/year maximum. Custom USF 200 Series and 300 Series Resistors: Operating Temperature: -40C to +85C. USF 200 Series and 300 Series Resistors are available, for high Lead Finish: Matte Tin (Sn) quantity applications, with custom performance: In the 200 Series, Absolute TC to as tight as 1 ppm/C is available for certain resistances. Ordering Information: Matched Ratio TC to as tight as 0.5 ppm/C for equal resistances. Matched Ratio TC can be provided in the 200 Series style bonded USF200 Series Part Numbers: Resistor pairs. USF240 - 10.0M - 0.01% - 2ppm Other Low TC Resistor Products from Caddock: Model Number Tolerance (0.01% or 0.1%) Type TF Low TC Ultra-Precision Film Resistors (1K to 125Meg) Resistor Value Type TK Low TC Precision Radial-Lead Film Resistors Type TG Low TC Precision High Voltage Resistors (up to 30KV) USF300 Series Part Numbers: Type USG Low TC Ultra-Precision High Voltage Resistors USF370 - 990K - 0.1% - 5ppm T912 and T914 Low TC Ultra-Precision Resistor Networks Type USVD Ultra-Precision Voltage Dividers (up to 2000 Volts) TC (5ppm or 10ppm) Model Number Type THV Precision High Voltage Dividers (up to 15KV) Tolerance (0.01% or 0.1%) Resistor Value Sales and Applications Engineering 17271 North Umpqua Hwy. ELECTRONICS, INC. Roseburg, Oregon 97470-9422 e-mail: caddock caddock.com web: www.caddock.com Phone: (541) 496-0700 For Caddock Distributors listed by country see caddock.com/contact/dist.html Fax: (541) 496-0408 2019 Caddock Electronics, Inc. 28 IL134.0819