Precision Metal Film Resistors

PR series

Low cost precision resistors

Tolerances down to ±0.1%

TCR down to 15ppm/°C

General Note

Welwyn Components reserves the right to make changes in product specification without notice or liability.

All information is subject to Welwyn’s own data and is considered accurate at time of going to print.

© Welwyn Components Limited · Bedlington, Northumberland NE22 7AA, UK

Telephone: +44 (0) 1670 822181 · Facsimile: +44 (0) 1670 829465 · Email: info@welwyn-tt.com · Website: www.welwyn-tt.com

PR4

PR5

Power rating at 70°C

watts

0.25

0.5

Resistance range

ohms

100R – 1M

Limiting element voltage

volts

250

350

TCR (20°C to 70°C)

ppm/°C

≤240K: 15, 25, 50

>240K: 25, 50

Resistance tolerance

%

≤500K: 0.1, 0.25, 0.5, 1

>500K: 0.25, 0.5, 1

Standard values

E24, E96

Thermal impedance

°C/watt

140

112

Ambient temperature range

°C

-55 to 155

Electrical Data

Physical Data

03.10

A subsidiary of

TT electronics plc

Welwyn Components

182

L

D

f

d

Construction

The resistance element is a precisely controlled thin film of

metal alloy sputtered on to a high purity ceramic core,

protected by a moisture-resistant, high dielectric strength

coating applied so that terminations remain completely clear.

This permits a well defined body length (clean lead to clean

lead dimension L).

Terminations

Material

Hot tin dipped copper wire

Strength

The terminations meet the requirements of

IEC 68.2.21

Solderability

The terminations meet the requirements of

IEC 115-1, Clause 4.17.3.2

Marking

25ppm/°C resistors are colour coded with 5 bands. The other

grades have an additional 6th band indicating TCR which is

orange for 15ppm/°C and red for 50ppm/°C.

Solvent Resistance

The body protection and marking are resistant to all normal

industrial cleaning solvents suitable for printed circuits.

Precision Metal

Film Resistors

PR series

• Low cost precision resistors

• Tolerances down to ±0.1%

• TCR down to 15ppm/°C

Dimensions (mm) & Weight (g)

PC

Min.

Wt. nom

mounting

bend

Type

L Max

D Max

f min

d nom

centres

radius

PR4

6.2

2.5

21

0.6

10.2

PR5

9.0

0.6

0.3

3.6

19.6

0.8

12.7

1.2

0.5

Resistors

06.18

General Note

TT Electronics reserves the right to make changes in product specification without notice or liability.

All information is subject to TT Electronics’ own data and is considered accurate at time of going to print.

© TT Electronics plc

www.ttelectronics.com/resistors

BI Technologies IRC Welwyn

All Pb-free parts comply with EU Directive 2011/65/EU amended by (EU) 2015/863 (RoHS3)

All Pb-free parts comply with EU Directive 2011/65/EU amended by (EU) 2015/863 (RoHS3)