Sales and Corporate Office

1717 Chicago Avenue

Riverside, California 92507-2364

Phone: (951) 788-1700

Fax: (951) 369-1151

Applications Engineering

17271 North Umpqua Hwy.

Roseburg, Oregon 97470-9422

Phone: (541) 496-0700

Fax: (541) 496-0408

e-mail: caddock@caddock.com • web: www.caddock.com

For Caddock Distributors listed by country see caddock.com/contact/dist.html

© 2004 Caddock Electronics, Inc.

CAD

K

DOC

A

B

.50 ±.125

(12.70 ±3.18)

.032 DIA.

(.81 DIA.)

.200 ±.020

(5.08 ±.51)

C

(seated height)

D

.160 ±.030

(4.06 ±.76)

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.

Circuit Board Trace

Circuit Board Trace

Front View

Side View

Top View

Dimensions in inches

and (millimeters)

Fig. 1

USF 200 Series

CADDOCK

USF240

0418

.50 ±.125

(12.70 ±3.18)

.032 DIA.

(.81 DIA.)

.075 ±.020

(1.91 ±.51)

A

B

C

(seated height)

D

Side View

Front View

Fig. 2

USF 300 Series

Dimensions in inches

and (millimeters)

CADDOCK

USF340

0412

Ordering Information USF300 Series:

Ordering Information USF200 Series:

USF370 - 990K - 0.10% - 5 ppm/°C

Model Number

Resistor Value

Tolerance

(0.01% or 0.10%)

USF240 - 10.0 Meg - 0.01% - 2 ppm/°C

Model Number

Resistor Value

Tolerance

(0.01% or 0.10%)

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

20.0 K

25.0 K

50.0 K

USF240 Standard Resistance Values:

Absolute Tolerance: ±0.01% or ±0.10%, Absolute TC: 2ppm/°C

90.0 K

99.0 K

100 K

200 K

USF270 Standard Resistance Values:

Absolute Tolerance: ±0.01% or ±0.10%, Absolute TC: 2ppm/°C

Standard Resistance Values:

Specifications:

Resistance Tolerance: ±0.01% or ±0.10 measured at +23°C ±2°C.

Absolute Temperature Coefficient: TC referenced to +25°C,

Δ

R taken at -40°C and +85°C.

Load Life Stability: 2,000 hours at +85°C at rated voltage, not to

exceed rated power, ΔR (+0.015 ±0.015)% max.

10,000 hours at +85°C at rated voltage, not to exceed rated

power, ΔR (+0.030 ±0.030)% max.

Thermal Shock: Mil-Std-202 Method 107 condition A, except min.

temp. is -40°C, ΔR ±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: -40°C to +85°C.

Leadwire: Solder Coated Copper.

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)

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

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.

990 K

USF271 Standard Resistance Values:

Absolute Tolerance: ±0.01% or ±0.10%, Absolute TC: 2ppm/°C

9.90 Meg

1.00 Meg 2.00 Meg

9.99 Meg 10.0 Meg

USF340 Standard Resistance Values:

Absolute Tolerance: ±0.01% or ±0.10%, Absolute TC: 5ppm/°C

USF370 Standard Resistance Values:

Absolute Tolerance: ±0.01% or ±0.10%, Absolute TC: 5ppm/°C

USF371 Standard Resistance Values:

Absolute Tolerance: ±0.01% or ±0.10%, Absolute TC: 5ppm/°C

50.0 Ω

100 Ω

200 Ω

350 Ω

400 Ω

500 Ω

700 Ω

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

990 K

1.00 Meg

1.98 Meg

2.00 Meg

19.8 Meg

500 K

990 K

999 K

1.00 Meg

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

4.00 Meg

5.00 Meg

9.90 Meg

9.99 Meg

19.98 Meg 20.0 Meg

10.0 Meg

5.00 Meg

25.0 Meg

Type USF Ultra-Stable Low TC Film Resistors

200 Series and 300 Series

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