Precision Metal
Film Resistors
RC SERIES
●
CECC released products with
low TCRs over a wide
resistance range
●
Resistance tolerance down to 0.05%
●
Express delivery available
●
Low noise and negligible voltage
coefficient
Electrical Data
RC55
COMMERCIAL
Power rating at 70°C
Resistance range
Limiting element voltage
Isolation voltage
TCR (20 to +70°C) & codes
Resistance tolerance
watts
ohms
volts
volts
ppm/°C
%
RC65
RC70
NOTES
0.25
0.5
1.0
1R to 4M
1R to 4M
1R to 10M
350
350
500
500
500
700
5(V), 10(T), 15(Y), 25(D), 50(C) & 100(Z)
0.05(W), 0.1(B), 0.25(C), 0.5(D) & 1(F)
See resistance
restrictions
APPROVED CECC 40101-004
H
J
K
K
L
Power rating at 70°C
watts 0.063
0.125
0.25
0.25
0.5
Resistance range
ohms 1R to 1M 1R to 1M 1R to 1M
10R to 1M
10R to 1M
Limiting element voltage
volts
200
200
250
250
350
Isolation voltage
volts
280
280
350
350
500
TCR & codes
ppm/°C
15(Y), 25(D), 50(C) & 100(Z)
Resistance tolerance (code)
%
0.05(W), 0.1(B), 0.25(C), 0.5(D) & 1(F)
APPROVED CECC 40101-804
Power rating at 70°C
watts
Resistance range
ohms
Limiting element voltage
volts
Isolation voltage
volts
TCR & codes
ppm/°C
Resistance tolerance (code)
%
Standard values
Thermal impedance
Ambient temperature range
A
0.125
1R to 1M
200
280
B
0.25
1R to 1M
250
350
B
C
0.25
0.5
10R to 1M
10R to 1M
250
350
350
500
15(T), 25(E) & 50(C)
0.05(W), 0.1(B), 0.25(C), 0.5(D) & 1(F)
E24, E96 preferred
70
-55 to +155
See resistance
restrictions
See resistance
restrictions
Any value
to order
°C/watt
°C
110
60
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, England Tel: 01670 822181 Fax: 01670 829465 Web: http://www.Welwyn-TT.co.uk
Issue A 07/99
173
Precision Metal
Film Resistors
RC SERIES
Physical Data
Dimensions (mm) & Weight (g)
PCB
mounting
centres
10.2
12.7
18.4
Min.
Bend
Radius
0.6
0.6
1.2
Type
RC55
RC65
RC70
L max
7.2
10.0
15.5
D max
2.5
3.7
5.5
f min
30
30
30
d nom
0.6
0.6
0.8
Wt. nom
0.24
0.40
1.15
d
D
L
f
CONSTRUCTION
A metal film is deposited onto a high quality ceramic
former. Nickel-plated steel caps are force fitted to the
former and termination wires are welded to the caps.
The resistor is adjusted to value by a helical cut in
the film and the body is protected with a specially
formulated epoxy coating.
TERMINATIONS
Material
Solder coated 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
Type reference, TCR code, resistance value and
tolerance code.
The resistance values conform to IEC 62.
SOLVENT RESISTANCE
The body protection and marking are resistant to all
normal industrial cleaning solvents suitable for
printed circuits.
Performance Data
Load at commercial rating: 1000 hours at 70°C
∆R%
Load at CECC rating: 1000 hours at 70°C
∆R%
Dry heat: 1000 hours at 155°C
∆R%
Shelf life: 12 months at room temperature
∆R%
Derating from rated power at 70°C
Short term overload
∆R%
Climatic
∆R%
Climatic category
Long term damp heat
∆R%
Temperature rapid change
∆R%
Resistance to solder heat
∆R%
Vibration and bump
∆R%
Noise (in a decade of frequency)
µV/V
Voltage coefficient of resistance
ppm/V
CECC 40101-004 CECC 40101-804 *ACTUAL PERFORMANCE
REQUIREMENTS REQUIREMENTS MAXIMUM
TYPICAL
0.3
0.1
0.5
0.5
0.3
0.05
0.5
0.5
**1.0
0.15
Not specified
Not specified
0.1
0.03
Zero at 155°C
50% at 125°C
0.1
0.1
0.1
0.02
0.5
0.5
0.3
0.1
55/155/56
55/125/56
55/155/56
0.5
0.5
0.5
0.1
0.1
0.1
**0.2
0.05
0.1
0.1
0.06
0.03
0.1
0.1
0.06
0.02
Not specified
Not specified
1.0
0.1
Not specified
Not specified
<1
Note: *An 0.01 ohm addition to be added to the performance claims of all resistors <10R.
** All products within the specified approved range meet CECC requirements.
© Welwyn Components Limited
Bedlington, Northumberland NE22 7AA, England Tel: 01670 822181 Fax: 01670 829465 Web: http://www.Welwyn-TT.co.uk
Issue A 07/99
174
Precision Metal
Film Resistors
RC SERIES
Table of Resistance Restrictions
TCR
ppm/°C
5
10
15
25
50
100
RC55
0.05%
.1 – .25%
10 to 500k 10 to 500k
10 to 1M 10 to 1M
10 to 1M
5 to 1M
10 to 1M
5 to 2M
10 to 1M
5 to 2M
10 to 1M
1 to 2M
TOLERANCE
RC65
.5 – 1%
0.05%
.1 – .25%
1 to 500k 10 to 500k 10 to 500k
1 to 1M
10 to 1M 10 to 1M
1 to 1M
10 to 1M
5 to 1M
1 to 2M
10 to 1M
5 to 2M
1 to 4M
10 to 1M
5 to 2M
1 to 4M
10 to 1M
1 to 2M
.5 – 1%
1 to 500k
1 to 1M
1 to 1M
1 to 2M
1 to 4M
1 to 4M
RC70
0.05%
.1 – .25%
10 to 750k 10 to 750k
10 to 1M 10 to 1M
10 to 1M 10 to 2M
10 to 1M 10 to 5M
10 to 1M 5 to 10M
10 to 1M 1 to 10M
.5 – 1%
1 to 750k
1 to 1M
1 to 2M
1 to 5M
1 to 10M
1 to 10M
APPLICATION NOTES
Matched Sets and Networks
Welwyn has many years experience in the supply of
matched set of precision resistors.
Resistors can be supplied matched for tolerance and
TCR down to ±0.02% and ±2ppm/°C, either as
separate resistors or pre-assembled and
encapsulated within a plastic box.
The individual resistors within a set or module can
be manufactured with a tolerance of ±0.05% and
TCR of ±5ppm/°C.
PACKAGING
The standard method of packaging RC55 resistors is
taped in ammo packs. Taped resistors on reel or
loose packed components can also be supplied by
special request. The standard packaging for RC65
and RC70 resistors is loose in boxes. By special
request the RC65 components can also be supplied
taped on reel or in ammo pack. In the case of tape
packed components the usable lead length is
reduced by the width of the tape.
5
f
1
6
52
f
2
6
Body location f
1
– f
2
≤
1.4 mm
STANDARD QUANTITIES PER PACKAGE
Type
Small Box
Large Box
Reel
Large Ammo Pack
RC55
250
1000
5000
1000
RC65
125
500
2500
1000
RC70
25
250
-
-
© Welwyn Components Limited
Bedlington, Northumberland NE22 7AA, England Tel: 01670 822181 Fax: 01670 829465 Web: http://www.Welwyn-TT.co.uk
Issue A 07/99
175
