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, -40°C to +85°C, ref. to +25°C 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 -40°C to +85°C, referenced to +25°C 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 • Ceramic package provides cool operation. outstanding low Absolute Temperature Coefficient 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 -40°C to +85°C, referenced to +25°C 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, -40°C to +85°C, referenced to +25°C Model Number @W a+t8ta5g°Ce OCpMoeanrx.t iiVnmouulotmaugse MRine.sistanceMax. Tolerance TCemoepfefircaietunrte Fig. A DimBensions inchesC (mm) D USF240 0.33 300 50 Ω 10 Meg 0.01% or 0.1% 2 ppm/°C 1 ( 1 .97.5005 ±±..5012)0 ( .93.7553 ±±..5012)0 (.1402.58 MMaaxx..) ( 1 .56.0204 ±±..05210) USF270 0.75 1,400 990 K 5 Meg 0.01% or 0.1% 2 ppm/°C 1 (13.85.0100 ±±..05210) ( 1 .25.0700 ±±..05210) (1.535.907 M Maaxx..) (13.43.5209 ±±..05210) USF271 0.75 2,500 9.9 Meg 10 Meg 0.01% or 0.1% 2 ppm/°C 1 (13.85.0100 ±±..05210) ( 1 .25.0700 ±±..05210) (1.535.907 M Maaxx..) (13.43.5209 ±±..05210) USF340 0.33 300 50 Ω 20 Meg 0.01% or 0.1% 150 p pppmm/°°CC or 2 ( 1 .97.5005 ±±..5012)0 ( .93.7553 ±±..5012)0 (1.309.053 M Maaxx..) ( 1 .56.0204 ±±..05210) USF370 0.75 1,400 990 K 10 Meg 0.01% or 0.1% 150 p pppmm/°°CC or 2 (13.85.0100 ±±..05210) ( 1 .25.0700 ±±..05210) (1.532.201 M Maaxx..) (13.43.5209 ±±..05210) 5 ppm/°C or 1.500 ±.020 .500 ±.020 .520 Max. 1.350 ±.020 USF371 0.75 2,500 19.8 Meg 25 Meg 0.01% or 0.1% 10 ppm°C 2 (38.10 ±.51) (12.70 ±.51) (13.21 Max.) (34.29 ±.51) Sales and Applications Engineering ELECTRONICS, INC. 17271 North Umpqua Hwy. 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

Type USF Ultra-Stable Low TC Film Resistors 200 Series and 300 Series Page 2 of 2 Standard Resistance Values: Fig. 1 USF240 Standard Resistance Values: Dimensions in inches USF 200 Series and (millimeters) Absolute Tolerance: ±0.01% or ±0.1%, Absolute TC: 2 ppm/°C 50.0 Ω 350 Ω 2.00 K 10.0 K 90.0 K 250 K 2.50 Meg 10.0 Meg 120000 ΩΩ 590000 ΩΩ 25..5000 KK 2205..00 KK 9190.00 KK 510.000 K Meg 59..0900 MMeegg Top View .155 ±.025 250 Ω 1.00 K 9.00 K 50.0 K 200 K 2.00 Meg 9.99 Meg A (3.94 ±.64) USF270 Standard Resistance Values: Front View 9A9b0s Kolute1 T.0o0le Mraengce2:.0 ±00 M.0e1g%5 .o0r0 ±M0e.1g%, Absolute TC: 2 ppm/°C CUAS1D9FD22O14C0K B (seatedC height) USF271 Standard Resistance Values: .032 DIA. .50 ±.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 Ω 400 Ω 1.80 K 10.0 K 50.0 K 180 K 500 K 2.00 Meg 9.99 Meg (5.08 ±.51) 100 Ω 500 Ω 2.00 K 18.0 K 90.0 K 198 K 990 K 4.00 Meg 10.0 Meg 200 Ω 700 Ω 4.00 K 20.0 K 99.0 K 200 K 999 K 5.00 Meg 19.8 Meg 350 Ω 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 +23°C ±2°C. .075 ±.020 A∆Rbs toalkuetne aTte -m40p°eCra atunrde +C8o5e°Cffi.cient: TC referenced to +25°C, A (1.91 ±.51) Load Life Stability: 2,000 hours at +85°C at rated voltage, not to Front View exceed rated power, ∆R (+0.015 ±0.015)% max. CADDOCK B C 10,000 hours at +85°C at rated voltage, not to exceed rated U1S9F23040 (seated height) power, ∆R (+0.030 ±0.030)% max. .032 DIA. .50 ±.125 Thermal Shock: Mil-Std-202 Method 107 condition A, except min. (.81 DIA.) (12.70 ±3.18) temp. is -40°C, ∆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 +(20ppm±20ppm)/yr. after 1 year. Extended shelf life (ten years) 10 ppm/year maximum. Custom USF 200 Series and 300 Series Resistors: Operating Temperature: -40°C to +85°C. Lead Finish: Matte Tin (Sn) 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 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 TC (5ppm or 10ppm) • Type USVD Ultra-Precision Voltage Dividers (up to 2000 Volts) Model Number Tolerance • Type THV Precision High Voltage Dividers (up to 15KV) Resistor Value (0.01% or 0.1%) Sales and Applications Engineering ELECTRONICS, INC. 17271 North Umpqua Hwy. 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