Ultra Precision
Metal Film Resistors
CAR series
Welwyn Components
•
Tolerance down to 0.01%
•
Low TCR’s
•
High reliability
•
Superior moisture performance
•
Non standard values available
•
Highest stability metal film available
•
Matched sets and networks
Electrical Data
CAR5
Power rating at 70°C
Power rating at 85°C
Resistance range
Limiting element voltage
TCR (20 to +70°C)
Resistance tolerance
Standard values
Thermal impedance
Ambient temperature range
°C/watt
°C
110
watts
watts
ohms
volts
ppm/°C
%
0.25
0.125
10R0 to 3M
250
CAR6
0.33
0.25
10R0 to 5M
350
CAR7
0.5
0.33
10R0 to 10M
500
See tolerance/TCR
combinations
below
60
Notes
5(V), 10(T), 15(Y), 25(D), 50(C)
0.01(L), 0.02(P), 0.05(W), 0.1(B), 0.25(C), 0.5(D) & 1(F)
E24, E96 preferred
70
-55 to +155
Table of Resistance Restrictions
Tolerance
TCR
ppm/°C 0.01-0.02%
5
1
10
15
25
50
50 to 300k
50 to 300k
50 to 300k
50 to 300k
50 to 300k
CAR5
0.05%
10 to 500k
10 to 1M
10 to 1M
10 to 1M
10 to 1M
0.1-1%
10 to 500k
10 to 1M
10 to 1M
10 to 1.5M
10 to 3M
0.01/0.02%
50 to 500k
50 to 500k
50 to 500k
50 to 500k
50 to 500k
CAR6
0.05%
10 to 500k
10 to 1M
10 to 1M
10 to 1M
10 to 1M
0.1-1%
10 to 500k
10 to 1M
10 to 1M
10 to 3M
10 to 5M
0.01-0.02%
50 to 750k
50 to 750k
50 to 750k
50 to 750k
50 to 750k
CAR7
0.05%
10 to 750k
10 to 1M
10 to 1M
10 to 1M
10 to 1M
0.1-1%
10 to 750k
10 to 1.5M
10 to 3.5M
10 to 5M
10 to 10M
Physical Data
Dimensions (mm) and Weight (g)
PCB
mounting
Type
CAR5
CAR6
CAR7
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
centres
10.2
12.7
18.4
Min
Bend
Radius
0.6
0.6
1.2
Note1: Based on sampling. 100% screened product is available.
Wt.
nom.
0.24
0.40
1.15
d
D
L
f
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
© 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
178
Ultra Precision
Metal Film Resistors
CAR series
Construction
Ceramic rods are coated with a metal film and plated steel
caps are force fitted. A helical cut is used to adjust the film to
its final value.
Termination wires are welded to the caps and the resistor is
protected with a specially formulated epoxy coating.
Welwyn Components
Marking
Type reference, TCR code, resistance value and tolerance
code.
The resistance value marking conforms to IEC 62.
Solvent Resistance
The body protection and marking are resistant to all normal
industrial cleaning fluids suitable for printed circuits.
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
Performance Data
Values 10
≤
250k
Actual Performance
Maximum
Load at rated power : 1000 hrs at 70°C (or 85°C)
Dry heat : 1000 hrs at 155°C
Shelf life : 12 months at room temperature
Derating from rated power at 70°C (or 85°C)
Short term overload
Climatic
Climatic category
Long term damp heat
Temperature rapid change
Resistance to solder heat
Vibration and bump
Noise (in a decade of frequency)
Voltage coefficient of resistance
∆R
%
∆R
%
∆R
%
∆R
%
µV/V
ppm/V
0.05
0.04
0.02
0.02
0.2
0.3
∆R
%
∆R
%
∆R
%
∆R
%
∆R
%
0.05
0.15
0.01
0.01
0.05
55/155/56
0.02
0.02
0.003
0.002
0.03
<0.05
0.2
0.25
0.05
0.06
1
0.2
Typical
0.02
0.08
0.003
0.001
0.02
Values > 250k
Actual Performance
Maximum
0.25
1
0.04
0.08
0.2
55/155/56
0.05
0.05
0.005
0.02
0.1
<0.05
Zero at 155°C
0.01
0.05
Typical
0.05
0.2
0.02
Zero at 155°C
Application Notes
Resistors can be supplied matched for tolerance and TCR
down to ±0.005% and ±1ppm/°C, respectively, 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 ±0.01% and a TCR of
±5ppm/°C.
Figure 1
5
f
1
6
52
f
2
6
Body location f
1
– f
2
≤
1.4 mm
© 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
179
Ultra Precision
Metal Film Resistors
CAR series
Welwyn Components
Ordering Procedure
Example: CAR5 with TCR of 5ppm/ °C at 31.6 kilohms and 0.02% tolerance in an ammo pack
box of 1000 pieces -
CAR5V–31K6P
I
Type
V
T
Y
TCR
5 ppm/
°C
10 ppm/
°C
15 ppm/
°C
D
C
25 ppm/
°C
50 ppm/
°C
Value (use IEC62 code)
Tolerance (use IEC62 code)
L
P
W
B
0.01%
0.02%
0.05%
0.1%
C
D
F
0.25%
0.5%
1%
Packing
I
Ammo
Bulk
CAR5, CAR6
CAR7
1000/box
250/box
Standard
For 5ppm/°C screened product, replace the packing suffix with
SC.
Example:
CAR5V-31K6PSC
© 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
11.09
179