Pulse Withstanding
Chip Resistors
PWC Series
Excellent pulse withstand performance
Improved working voltage
Improved power rating
Standard chip sizes (0805 to 2512)
Custom designs available
Welwyn Components
Electrical Data
Size
Power @70°C
Resistance range
Tolerance
LEV
TCR
Operating temperature
Thermal Impedance
Pad / trace area*
Values
Pulse capability
W
Ohms
%
V
ppm/°C
°C
°C/W
mm
2
220
40
160
50
150
200
-55 to +155
80
60
50
100
0805
0.125
1206
0.33
1R0 to 10M
10R to 1M: 0.5, All values: 1, 5
400
500
<10R:200
≥10R:100
2010
0.75
2512
1.5
E24 or E96 preferred other values to special order
See graphs - full application note available on request
*Recommended minimum pad & adjacent trace area for each termination for rated power dissipation on FR4 PCB
Physical Data
Dimensions of PWC resistors are given below in mm and weight in g
L
0805
1206
2010
2512
2.0±0.3
3.2±0.4
5.1±0.3
6.5±0.3
W
1.25±0.2
1.6±0.2
2.5±0.2
3.2±0.2
T max
0.6
0.7
0.8
0.8
A
0.3±0.15
0.4±0.2
0.6±0.3
0.6±0.3
B
0.9 min
1.7 min
3.0 min
4.4 min
C
0.3±0.1
0.4±0.15
0.6±0.25
0.6±0.25
Wt.
0.009
0.020
0.036
0.055
A
B
L
A
W
T
Wrap-around terminations
(3 faces)
Construction
Thick film resistor material, overglaze and organic protection
are screen printed on a 96% alumina substrate. Wrap-around
terminations have an electroplated nickel barrier and solder
coating, this ensures excellent ‘leach’ resistance properties
and solderability.
Marking
Components are not marked. Reels are marked with type,
value, tolerance, date code and quantity.
Solvent Resitance
The body protection is 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
07. 08
© 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
37
Pulse Withstanding
Chip Resistors
PWC Series
Welwyn Components
Performance Data
Size
Load at rated power:
Shelf life test:
Overload:
Dry heat:
1000 hours at 70°C
Maximum
R%
R%
R%
R%
R%
R%
R%
Volts
1
0.1
Zero at 155°C
1
1
1
0.25
0.25
500
12 months at room temperature
Typical
0.25
0.02
0.1
0.2
0.25
0.05
0.05
Derating from rated power at 70°C
6.25 x rated power for 2 seconds
1000 hours at 155°C
Long term damp heat
Temperature rapid change
Resistance to solder heat
Voltage proof
Note: A 0.01 Ohm addition to be added to the performance of all resistors <10 Ohms.
Pulse Performance Data
1.2/50µs Lightning Surge
10000
Peak voltage (volts)
1000
0805
1206
2010
2512
100
Lightning Surge
Resistors are tested in accordance with
IEC 60 115-1 using both 1.2/50µs and
10/700µs pulse shapes. 10 pulses are
applied The limit of acceptance is a shift
in resistance of less than 1% from the
initial value
10
1
10
100
1000
10000
Value (ohms)
100000
1000000
10000000
10/700µs Lightning Surge
10000
Peak Voltage (Volts)
1000
0805
1206
2010
2512
100
10
1
10
100
1000
10000
Value (ohms)
100000
1000000
10000000
© 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
07. 08
Pulse Withstanding
Chip Resistors
PWC Series
Welwyn Components
Pulse Performance Data
1000
Single Pulse
Pulse Power P (W)
100
0805
1206
2010
2512
10
Single Impulse
The single impulse graph is the result of
50 impulses of rectangular shape
applied at one minute intervals. The
limit of acceptance was a shift in
resistance of less than 1% from the
initial value. The power applied was
subject to the restrictions of the
maximum permissible impulse voltage
graph as shown.
Pulse Power P (W)
1
0.0001
0.001
0.01
Pulse Duration ti (s)
0.1
1
100
Continuous Pulses
Continuous Load Due to
Repetitive Pulses
The continuous load grpah was
obtained by applying repetitive
rectangular pulses where the pulse
period was adjusted so that the average
power dissipated in the resistor was
equal to its rated power at 70°C. Again
the limit of acceptance was a shift in
resistance of less than 1% from the
initial value.
10
0805
1206
2010
2512
1
0.1
0.0001
0.001
0.01
Pulse Duration ti (s)
0.1
1
10000
Pulse Voltage
Pulse Voltage (Volts)
1000
0805
1206
2010
2512
100
10
0.0001
0.001
0.01
Pulse Duration ti (s)
0.1
1
© 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
07.08
Pulse Withstanding
Chip Resistors
PWC Series
Welwyn Components
Thermal Performance Data
125
100
75
50
25
0
-15
70
Ambient Temperature /°C
155
Temperature Rise /°C
% of Rated Power
Temperature Derating Curve
Temperature Rise Curves
80
60
40
20
0
0
0.5
1
Power Dissipation /W
1.5
0805
1206
2010
2512
Packaging
0805 and 1206 PWC series resistors are
supplied on 8mm carrier tape and 7 inch
reels as per IEC 286-3, quantity per
reel; 3000.
Marking
T
2
P
0
D
0
P
2
8mm tape: 9mm ± 0.5
12mm tape: 13mm ± 0.5
33 ± 1.0
9.0
+ 0.1
- 0.15
T
2010 and 2512 PWC series resistors are
supplied on 12mm carrier tape and 7
inch reels as per IEC 286-3, quantity per
reel; 2010 : 3000pcs; 2512 : 1800pcs.
Reels of 1000pcs are available on
request.
Tape dimensions in mm
13 ± 0.5
178 ± 2
80 ± 2
B
0
F
E
T
1
A
0
K
0
P
1
D
1
2.5 ± 0.5
0.8 ± 0.15
0805
1206
2010
2512
W
±0.3
8
8
12
12
P1
±0.1
4
4
4
8
P0
±0.1
4
4
4
4
P2
±0.05
2
2
2
2
D0
±0.1
1.5
1.5
1.5
1.5
D1
±0.2
1
1
1.5
1.5
E
±0.1
1.75
1.75
1.75
1.75
F
±0.05
3.5
3.5
5.5
5.5
A0
±0.1
1.65
1.95
2.79
3.61
B0
±0.1
2.45
3.55
5.89
6.96
K0
±0.1
0.8
1.0
0.91
1.17
T
±0.05
0.2
0.2
0.28
0.28
T1
nom
0.05
0.05
0.06
0.06
Application Notes
PWC resistors are ideally suited for handling by automatic
methods due to their rectangular shape and the small
dimensional tolerances. Electrical connection to a ceramic
substrate or to a printed circuit board can be made by reflow
or wave soldering of wrap-around terminations.
Wrap-around terminations provide good leach properties and
ensure reliable contact. Due to the robust construction, the
PWC can be immersed in the solder bath for 30 seconds at
260°C. This enables the resistor to be mounted on one side
of a printed circuit board and wire-leaded components
applied on the other side.
PWC resistors themselves can operate at a maximum
temperature of 155°C. For soldered resistors, the joint
temperature should not exceed 110°C. This condition is met
when the stated power levels at 70°C and recommended pad
and trace areas are used. Allowance should be made if
smaller areas of copper are used.
A full Application Note on the PWC Series is available.
Ordering Procedure
Specify type reference etc as shown in this example of
PWC2512 10K ohms 1%.
Type
Size
Value (use IEC62 code)
Tolerance (use IEC62 code)
D
F
J
0.5%
1%
5%
PWC
2512
-
10K
F
© 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
07. 08
G
T2
±0.15
1.1
1.3
1.21
1.45
W
