Overall Product: Caddock USF Ultra-Stable Low TC Film Resistors (200 & 300 Series)

️· Purpose: Precision resistors designed for applications requiring high stability and low temperature coefficient.
️· Series: Two main series - USF200 and USF300. The series dictates some of the performance characteristics.
️· Manufacturer: Caddock Electronics, Inc.

Key Specifications (General to both series, with some differences noted)

️· Resistance Range: (See 'Standard Resistance Values' sections - detailed below). A *very* wide range of values is listed.
️· Tolerance: ±0.01% or ±0.10% (selectable)
️· Absolute Temperature Coefficient (TC):
- USF200 Series: Typically 2 ppm/°C. (Can be as tight as 1 ppm/°C for certain resistances on a custom basis.)
- USF300 Series: 5 ppm/°C
️· Operating Temperature: -40°C to +85°C
️· 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.
️· Leadwire: Solder Coated Copper

Standard Resistance Values (Listed by Series - Partial List)

*These are *examples* from the text. The list is not exhaustive. I'm grouping them by series.*

USF240 Standard Resistance Values (2 ppm/°C):

️· 50.0 Ω
️· 100 Ω
️· 200 Ω
️· 250 Ω
️· 350 Ω
️· 500 Ω
️· 900 Ω
️· 1.00 K
️· 2.00 K
️· 2.50 K
️· 5.00 K
️· 9.00 K
️· 10.0 K
️· 18.0 K
️· 20.0 K
️· 25.0 K
️· 50.0 K
️· 100 K
️· 200 K
️· 250 K
️· 500 K
️· 1.00 Meg
️· 2.00 Meg
️· 2.50 Meg
️· 5.00 Meg
️· 9.90 Meg
️· 9.99 Meg
️· 10.0 Meg

USF270 & 271 Standard Resistance Values (2 ppm/°C):

️· (Similar range to USF240 – focuses on common values, with a focus on higher resistance).

USF340 & 370 Standard Resistance Values (5 ppm/°C):

️· (Similar range to USF240 – focuses on common values)

USF371 Standard Resistance Values (5 ppm/°C):

️· (Similar range to USF240 – focuses on common values)

Custom Options:

️· Tighter TC: USF200 series can achieve 1 ppm/°C for certain resistances.
️· Matched Ratio TC: Available in the 200 series, for pairs of resistors with a tight correlation in temperature response (0.5 ppm/°C).

Other Caddock Low TC Resistor Products (Mentioned for reference):

️· Type TF (1K to 125Meg)
️· Type TN
️· Type TK
️· Type TG (up to 30KV)
️· T912 and T914
️· Type USVD (up to 2500V)
️· Type THV (up to 20KV)

Ordering Information (Example):

️· USF240 – 10.0 Meg – 0.01% – 2 ppm/°C (This format indicates Series, Resistance, Tolerance, and TC)
️· USF370 – 990K – 0.10% – 5 ppm/°C (Same format as above)