WL series
Miniature Wirewound
Current Sense
F e at u r e s
• Ultra-low ohmic value series for Current Sensing
applications
• Very low inductance (<1nH at 1MHz Test)
• Miniaturized dimensions, Better power to dimen-
sion ratios
• Use of the highest quality standard (96% Alumina)
ceramic core
• Manufacturing process–Wire winding/Spot
Welding–by Computer Numerical Control (CNC)
machine tools to ensure consistency of product
quality.
• Encapsulated by epoxy molding compound
• Advanced IC encapsulation mold/die technologies
Resistance Range (Ω)
0.005-0.100
0.005-0.100
0.010-0.100
s e r i e s s P e c i F i c at i O N s
Type
WLA
WLB
WLC
Power Rating (watts)
0.5
1
2
characteristics
Ceramic Core
CeramTec Rubalit® 96% alumina
End Caps
Stainless steel, precision formed
Leads
Copper wire, 100% Sn (Lead Free) coated
Resistance Wire
CN49W alloy TC ±20ppm/°C
Encapsulation
SUMICON 1100/1200 Epoxy molding compound for IC encapsulation
Standard Tolerance
F (1.0%), J (5.0%)
Temperature Coefficient
±300ppm/°C for ≤0.03Ω; ±100ppm/°C for ≥0.033Ω
Maximum Working Voltage
√PxR
Derating
100
Percent Rated Power
80
60
40
20
0
0
25 50 75 100 125 150 175
Ambient Temperature,
ϒ
C
P e r F O r M a N c e D ata
Test Conditions Of Test
Thermal Shock
Rated power applied until thermal stability, -55°C +0°C,-5°C,15min.
Short-time Overload
5 times rated wattage for 5 seconds
Solderability
Method 208 of MIL-STD-202
Terminal Strength
Pull test:10 pounds, 5 to10 seconds, Twist test: 1080°, 5 second/rotation
Dielectric Withstanding Voltage
500 Volts rms for 1W. 1 minute
High Temperature Exposure
Exposed to an ambient temperature of 275 +5/-0°C for 250 ±8 hours,
Moisture Resistance
MIL-STD-202 Method 106, 7b not applicable
Low Temperature Storage
Cold chamber at a temperature of -65 ±2°C for 24 ±4 hours
Vibration, High Frequency
Frequency varied 10 to 2000Hz, 200G peak, 2 directions 6 hours each
Load Life
1000/2000 hours at rated power, +25°C, 1.5 hours “On”, 0.5 hours “Off”
Performance
±2.0%
±2.0%
±2.0%
±1.0%
±1.0%
±5.0%
±2.0%
±2.0%
±1.0%
±5.0%
(continued)
50
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