Ultra Precision
Metal Film Resistors
CAR series
•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
Tolerance
TCR CAR5 CAR6 CAR7
ppm/°C 0.01-0.02% 0.05% 0.1-1% 0.01/0.02% 0.05% 0.1-1% 0.01-0.02% 0.05% 0.1-1%
5 50 to 300k 10 to 500k 10 to 500k 50 to 500k 10 to 500k 10 to 500k 50 to 750k 10 to 750k 10 to 750k
10 50 to 300k 10 to 1M 10 to 1M 50 to 500k 10 to 1M 10 to 1M 50 to 750k 10 to 1M 10 to 1.5M
15 50 to 300k 10 to 1M 10 to 1M 50 to 500k 10 to 1M 10 to 1M 50 to 750k 10 to 1M 10 to 3.5M
25 50 to 300k 10 to 1M 10 to 1.5M 50 to 500k 10 to 1M 10 to 3M 50 to 750k 10 to 1M 10 to 5M
50 50 to 300k 10 to 1M 10 to 3M 50 to 500k 10 to 1M 10 to 5M 50 to 750k 10 to 1M 10 to 10M
Dimensions (mm) and Weight (g)
PCB Min
mounting Bend Wt.
Type L Max D Max f min d nom. centres Radius nom.
CAR5 7.2 2.5 30 0.6 10.2 0.6 0.24
CAR6 10.0 3.7 30 0.6 12.7 0.6 0.40
CAR7 15.5 5.5 30 0.8 18.4 1.2 1.15
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
CAR5 CAR6 CAR7 Notes
Power rating at 70°C watts 0.25 0.33 0.5
Power rating at 85°C watts 0.125 0.25 0.33
Resistance range ohms 10R0 to 3M 10R0 to 5M 10R0 to 10M
Limiting element voltage volts 250 350 500
TCR (20 to +70°C) ppm/°C 5(V), 10(T), 15(Y), 25(D), 50(C) See tolerance/TCR
Resistance tolerance %
0.01(L), 0.02(P), 0.05(W), 0.1(B), 0.25(C), 0.5(D) & 1(F)
combinations
Standard values E24, E96 preferred below
Thermal impedance °C/watt 110 70 60
Ambient temperature range
Note1: Based on sampling. 100% screened product is available.
°C -55 to +155
Electrical Data
Table of Resistance Restrictions
Physical Data
A subsidiary of
TT electronics plc
Welwyn Components
178
L
Df
d
1
Figure 1
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.
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
Ultra Precision
Metal Film Resistors
CAR series
© 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
Welwyn Components
Values 10 ≤250k Values > 250k
Actual Performance Actual Performance
Maximum Typical Maximum Typical
Load at rated power : 1000 hrs at 70°C (or 85°C) ∆R % 0.05 0.02 0.25 0.05
Dry heat : 1000 hrs at 155°C ∆R % 0.15 0.08 1 0.2
Shelf life : 12 months at room temperature ∆R % 0.01 0.003 0.04 0.02
C°551 ta oreZC°551 ta oreZ)C°58 ro( C°07 ta rewop detar morf gnitareD
Short term overload ∆R % 0.01 0.001 0.08 0.01
Climatic ∆R % 0.05 0.02 0.2 0.05
65/551/5565/551/55yrogetac citamilC
Long term damp heat ∆R % 0.05 0.02 0.2 0.05
Temperature rapid change ∆R % 0.04 0.02 0.25 0.05
Resistance to solder heat ∆R % 0.02 0.003 0.05 0.005
Vibration and bump ∆R % 0.02 0.002 0.06 0.02
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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.
Performance Data
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.
52
f1f2
66
5
Body location f1 – f2≤ 1.4 mm
Ultra Precision
Metal Film Resistors
CAR series
© 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
11.09
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 -
C A R 5 V – 3 1 K 6 P I
Type
TCR
V
5 ppm/ °C
D
25 ppm/ °C
T
10 ppm/°C
C
50 ppm/ °C
Y
15 ppm/ °C
Value (use IEC62 code)
Tolerance (use IEC62 code)
L
0.01%
C
0.25%
P
0.02%
D
0.5%
W
0.05%
F
1%
B
0.1%
Packing
Ammo
CAR5, CAR6
1000/box
Standard
Bulk
CAR7
250/box
For 5ppm/°C screened product, replace the packing suffix with SC. Example: CAR5V-31K6PSC