Precision Metal
Film Resistors
PR series
Welwyn Components
•
Low cost precision resistors
•
Tolerances down to ±0.1%
•
TCR down to 15ppm/°C
Electrical Data
PR4
Power rating at 70°C
Resistance range
Limiting element voltage
TCR*
Resistance tolerance
Standard values
Thermal impedance
Ambient temperature range
°C/watt
°C
watts
ohms
volts
ppm/°C
%
0.25
100R – 240K
250
25
0.1, 0.25, 0.5, 1
E192
140
-55 to 155
PR5
0.5
100R – 1M
350
25
0.1, 0.25, 0.5, 1
E192
112
*15ppm/°C available by request
Physical Data
Dimensions (mm) & Weight (g)
PCB
Min.
mounting bend
radius
Wt.nom
0.6
1.2
0.3
0.5
d
D
L
f
Type
PR4
PR5
L Max
6.2
9.0
D Max
2.5
3.6
f min
21
19.6
d nom
0.6
0.8
centres
10.2
12.7
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
Strength
Solderability
Solder-coated copper wire.
The terminations meet the requirements of
IEC 68.2.21
The terminations meet the requirements of
IEC 115-1, Clause 4.17.3.2
Marking
Resistors are colour coded with 5 bands. IEC 62 colours are
used.
Solvent Resistance
The body protection and marking are resistant to all normal
industrial cleaning solvents suitable for printed circuits.
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.
A subsidiary of
TT electronics plc
Issue C · 04.03
© 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
182
WELWYN [ WELWYN COMPONENTS LIMITED ]
