Features
■ Surge withstand IEC 61000-4-5 1.2/50 µs
■ Low thermal resistant ceramic core
■ E24 resistance values
■ RoHS compliant*
■ Wide power range (1~8 W)
■ Coating material meets UL 94V-0
requirements
Applications
■ Smart meters
■ Renewable energy
■ Industrial
■ Power supplies/chargers
■ Lighting
■ Instruments/gauges
■ White goods
WS Series
High Surge Withstand Wirewound Resistor
*RoHS Directive 2002/95/EC Jan. 27, 2003 including annex and RoHS Recast 2011/65/EU June 8, 2011.
Specifi cations are subject to change without notice.
The device characteristics and parameters in this data sheet can and do vary in different applications and actual device performance may vary over time.
Users should verify actual device performance in their specifi c applications.
*RoHS COMPLIANT
Electrical Characteristics
Resistance Range ................................................ See Popular Resistance Values Table
Power Rating @ 70 °C
WS1M, WS1A ........................................................................................................1 W
WS2M, WS2A ........................................................................................................2 W
WS3M, WS3A ........................................................................................................3 W
WS5M, WS5A ........................................................................................................5 W
WS7M, WS7A ........................................................................................................7 W
WS8M ....................................................................................................................8 W
Tolerance ....................................................................................................................5 %
Operating Temperature .........................................................................-55 °C to +200 °C
Temperature Coeffi cient ..............................................................................±200 ppm/°C
Maximum Voltage ....................................................................................................
√P*R
Physical Characteristics
Resistor .................................................................... Low thermal resistant ceramic core
Lead Wire ......................................................................................Tin-plated copper wire
Coating Material ............................................................... Meets UL 94V-0 requirements
Environmental Characteristics
Test Conditions Specifi cation
Short Time Overload 10 times rated power for 5 seconds. ΔR≤±(5 % ± 0.05 Ω)
Solderability 245 ±3 °C for 2.5 ±0.5 seconds. Over 95 % coverage
Resistance to 260 ±5 °C for 10 ± 1 seconds. ΔR≤±(1 % + 0.05 Ω)
Solder Heat
Temperature Cycle 5 cycles, -55 °C ±3 °C for 30 minutes, Room temperature for ΔR≤±(2 % + 0.05 Ω)
15 minutes, +155 ±2°C for 30 minutes, Room temperature for
15 minutes
Dielectric Strength Test voltage >500 Vrms for >1 minute. Pass
Insulation Resistance Test voltage >500 Vrms for 1 minute. >109 Ω
Load Life Humidity Rated continuous voltage for 1000 hours, 1.5 hours ON and ΔR≤ ±(5 % + 0.05 Ω)
0.5 hours OFF at 90~95 % relative humidity and test temperature
of 40 °C ±2 °C.
Load Life Rated continuous voltage for 1000 hours, 1.5 hours ON and ΔR≤±(5 % + 0.05 Ω)
0.5 hours OFF at a test temperature of 70 °C ±2 °C.
1000 hours at rated power.
Surge IEC 61000-4-5 1.2/50 μs exponential. ΔR≤ ±(5 % + 0.05 Ω)
Popular Resistance Values
Code R Value
15R0 15 Ω
20R0 20 Ω
22R0 22 Ω
33R0 33 Ω
47R0 47 Ω
Code R Value
68R0 68 Ω
1500 150 Ω
1001 1K Ω
3301 3.3K Ω
Other E24 resistance values available upon request.
How to Order
WS 3 M 22R0 J
Product Series
WS = Wirewound, High
Surge Withstand
Power Rating
1 = 1 Watt
2 = 2 Watts
3 = 3 Watts
5 = 5 Watts
7 = 7 Watts
8 = 8 Watts
Pin Style
A = Axial Standard Version
M = Axial Miniaturized Version
Resistance Code
• R<100 ohms:
“R” represents decimal point
(example: 22R0 = 22 ohms)
• R≥100 ohms:
First three digits are signifi cant,
fourth digit represents number of
zeros to follow
(example: 1001 = 1K ohms)
Resistance Tolerance
J = ±5 %
