Chip Resistors

(PWR)

Pulse Withstanding Chip Resistors (PWR) Application & Soldering Notes

Today's electronic devices are becoming smaller and smaller. The requirement, in particular, for pulse withstand capability is growing due to the need to protect sensitive modern electronic systems.

To meet this demand Token Electronics have designed a Pulse Withstanding Chip Resistor (PWR Series). The enhanced performance of the chips is made possible by the precise use of the best resistance inks and a closely controlled production process.

Application Notes:

  1. Applications vary from line protection for telecommunications to surge withstanding resistors for use in circuit breakers. Details of a typical telecomm and power supply application are given below.
  2. Telephone lines can be subjected to a large range of voltage disturbances, many of which can damage switching equipment. This has led to the need for circuit protection against both high voltage transients, usually of short duration caused by lighting strikes and overloads of longer duration, due to direct connection to mains power lines.
  3. These two faults are separated into primary and secondary protection.
    1. Primary protection handles the high voltage transients, and is usually located within the exchange.
    2. Secondary protection is usually built into the equipment to be protected, and deals with both current and voltage limiting.
  4. Voltage limiting prevents damage to the equipment and shock hazards, and current limiting prevents damage to wiring.
  5. To determine the suitability of a PWC series chip resistors for your application refer to the pulse withstanding data as given lighting surge performance using both 1.2/50μs and 10/700μs pulse shapes.

Soldering Notes:

  1. Electrical connection to a ceramic substrate or to a printed circuit board can be made by
    reflow or wave soldering of wrap-around terminations.
  2. Wrap-around terminations provide good leach properties and ensure reliable contact.
  3. Due to the robust construction, the PWR can be immersed in the solder bath for 30 seconds at 260°C.
  4. This enables the resistor to be mounted on one side of a printed circuit board and wire-leaded components applied on the other side.
  5. PWR resistors themselves can operate at a maximum temperature of 155°C.
  6. For soldered resistors, the joint temperature should not exceed 110°C.
  7. This condition is met when the stated power levels at 70°C and recommended pad and trace areas are used.
  8. Allowance should be made if smaller areas of copper are used.

Environmental Characteristics (PWR)

Power Derating Curve (PWR)
Power Derating Curve (PWR)
Test Item Specification Test Method
Short Time Overload ±0.5% JIS-C-5201-1 4.13
IEC-60115-1 4.13
RCWV*2.5 or Max Overloading Voltage whichever is lower for 5 seconds
Leaching Individual leaching area ≥5%
Total leaching area ≥10%
JIS-C-5201-1 4.18
IEC-60068-2-58 8.2.1
-55°C~155°C, 5 cycles
Temperature Coefficient of Resistance As Spec. JIS-C-5201-1 4.8
IEC-60115-1 4.8
+25/-55/+25/+125/+25°C
Load Life
(Endurance)
±(1%+0.05Ω) JIS-C-5201-1 4.25
IEC-60115-1 4.25.1
RCWV, 70°C, 1.5 hours ON, 0.5 hours OFF,
total 1000~1048 hours
Humidity (Steady State)
(Damp Heat with Load)
±(0.5%+0.05Ω) JIS-C-5201-1 4.24
IEC-60115-1 4.24
40±2°C, 90~95%RH, RCWV 1.5 hours ON,
0.5 hours OFF, total 1000 hours
Resistance to Dry Heat ±0.5% JIS-C-5202-7.2
96 hours @ +155°C without load
Low Temperature Operation ±0.5% JIS-C-5202-7.1
1hour,-65°C followed by 45 minutes of RCWV
Dry Heat ±(0.5%+0.05Ω) JIS-C-5201-1 4.23
IEC-60115-1 4.23.2
at +155°C for 1000 hrs. 2010, 2512 sizes: 2mm; Other sizes: 3mm
Bending Strength ±(1%+0.05Ω) JIS-C-5201-1 4.33
IEC-60115-1 4.33
Bending once for 5 seconds. 2010, 2512 sizes: 2mm; Other sizes: 3mm
Resistance to Soldering Heat ±(0.5%+0.05Ω) JIS-C-5201-1 4.18
IEC-60115-1 4.18
260±5°C, 10±1seconds
Solderability 95% min coverage JIS-C-5201-1 4.17
IEC-60115-1 4.17
245°C±5°C for 3 seconds
Dielectric Withstand Voltage
(Voltage Proof)
No breakdown or flashover JIS-C-5201-1 4.7
IEC-60115-1 4.7
1.42 times Max. Operating Voltage for 1 minute
Insulation Resistance >10GΩ JIS-C-5201-1 4.6
IEC-60115-1 4.6
Max. Overload Voltage for 1 minute
Note: Storage Temperature: 25±3°C; Humidity: <80%RH
  • Rated continuous Working Voltage (RCWV) = Power Rating × Resistance Value (Ω) or Max. Operating voltage whichever is lower.
  • Storage Temperature: 15°C~28°C; Humidity < 80%RH;

Lightning Surge of Pulse Withstanding Chip Resistor (PWR)

(PWR) Series 1.2/50µs Lightning Surge
1.2/50µs Lightning Surge Chip Resistor (PWR)
(PWR) 10/700µs Lightning Surge
10/700µs Lightning Surge Chip Resistor (PWR)
Note: Lightning Surge of Pulse Withstanding Chip Resistors are tested in accordance with IEC 60 115-1 using both 10/700μs and 1.2/50μs pulse shapes.
The limit of acceptance is a shift in resistance of less than 1% from the initial value.

Pulse withstanding capacity of Pulse Withstanding Chip Resistor (PWR)

(PWR) Pulse withstanding capacity
Pulse withstanding capacity of Chip Resistor (PWR)
Note: The single impulse graph is the result of 50 impulses of rectangular shape applied at one-minute intervals.
The power applied was subject to the restrictions of the maximum permissible impulse voltage graph shown.
The limit of acceptance was a shift in resistance of less than 1% from the initial value.

Continuous Pulse of Pulse Withstanding Chip Resistor (PWR)

(PWR) Continuous Pulse
Continuous Pulse of Pulse Withstanding Chip Resistor (PWR)
(PWR) Pulse Voltage
Pulse Voltage of Chip Resistor (PWR)
Note: The continuous load graph 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.

Order Codes (PWR)

PWR 05 D TR C1 W 10R0  
12345678
Part Number
Dimensions
03 EIA0603
05 EIA0805
06 EIA1206
13 EIA1210
10 EIA2010
12 EIA2512
Resistance
Tolerance(%)
D ±0.5%
F ±1%
J ±5%
Package
P Bulk
TR Taping Reel
TCR
(ppm/°C)
C1 ±100ppm/°C
C ±200ppm/°C
Power Rating
(W)
A 1.5W
O 1/3W
Q 3/4W
T 1W
U 1/2W
V 1/4W
P 1/5W
W 1/8W
X 1/10W
Resistance
(Ω)
10R0 10Ω
1000 100Ω
2201 2K2Ω
1002 10KΩ
1003 100KΩ
1004 1MΩ
1005 10MΩ
Marking
  Standard Marking
for E96/E24
N No Marking