General catalogue - Caddock Electronics - #36

The USF Ultra-Stable Low TC Ulira-Precision Film Resistors were developed lo 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 — Maximum Absolute TC 5 ppm'°C Tolerance: ±0.0i%ori0.i0%.

commonly required in high accuracy analog design. These values

were selected and optimized for produceability and performance. J'JU Series naxhed pairs' ive ova: able with ratio TC as tight as 0.5 ppm/T. Contact Applications Engineering. Ceramic package provides cool operation.

■ Constructed with two selected USF 300 Series Resistors bonded back to back to achieve outstanding low Aüsc: i.te Ternsrature Coefficient

i. The res' -parallel on the circuit ZERO Nominal TC --40°C to +S5°C,

tors are offered in

J in precision analog design. These standard resistance values can be used in precise amplifier gain setting, precise

voltage dividers with up to 2500 volt input voltage.

Extremely Low Power Coefficient (Wattage Coefficient): Type USF resistors are constructed with an a uninum oxide ceramic sandwich which provides great thermal conductivity. The ceramic sandwich package very effectively minimizes the power coefficient drift. Power coelficient 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 ot the resistor element results in TC dritt (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 LowTC foil resistors cannot provide this oufstanding benefit since the plastic impedes the flow of heat, causing greater temperature rise at the resistor element and greater seif-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.

Type USF 300 Series Ultra-Stable Resistors ■ ZERO Nominal TC - Max Absolute TC: 5 ppm/°C, -40°C to +85°C, referenced to +25°C