F E A T U R E S
S P E C I F I C A T I O N S
• WHM, UltraHigh ohmic value
precision series,
Material
WH/WN Series
Ceramic Core: CeramTec
Rubalit® 96% alumina
End Caps: Stainless steel, preci-
sion formed
Leads: Copper wire,100% Sn
(lead free) coated
ISAOHM alloy resistance wire
TC+/-20ppm/°C
Encapsulation: SUMICON 1100/
1200 Epoxy molding compound
for IC encapsulation
• WNM, Aryton Perry winding Non-
Inductive available.
Inductance <1nH at 1MHZ test,
• Designed to meet the most strin-
gent MIL-R-26F, MIL-STD-202
standard requirements
• Miniaturized Better power to
dimension ratios
• Use of the highest quality stan-
dard (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
Miniature Molded Wirewound
0.984 / 25
L
D
d
�
ꢀ
Power Resistance
Rating
Type (watts)
Range
Dim. L
(mm/in)
Dim. D
(mm/in)
Dim. d
(mm/in)
(Ω)
Electrical
Standard Tolerance: F (1.0%),
J (5.0%)
Temperature Coefficient
(ppm/°C):
±90 for 0.100Ω
±20 for >0.100Ω
Maximum Working Voltage:
(PxR)1/2
Derating: Linearly from
100% @ +70°C to
0% @ +150°C.
WHA
WNA
WHB
WNB
WHC
WNC
0.5
0.100 - 1.0K 5.08 / 0.200 2.54 / 0.100 0.60 / 0.024
0.100 - 250
0.100 - 4.0K 7.00 / 0.276 3.00 / 0.120 0.60 / 0.024
0.100 - 1.0K
0.10 - 8.0K 11.4 / 0.450 6.86 / 0.270 0.80 / 0.031
0.10 - 2.0K
1
2
• Advanced IC encapsulation
mold/die technologies
P E R F O R M A N C E C H A R A C T E R I S T I C S
Test
Conditions of Test
Performance
Thermal Shock
Rated power applied until thermal stability,
-55°C +0°C,-5°C,15min.
±0.2%
Operating Temp: -55°C to
+150°C
Short-time Overload 5 times rated wattage for 5 seconds
±0.2%
±0.2%
±0.1%
Solderability
Method 208 of MIL-STD-202
Pull test:10 pounds, 5 to10 seconds, Twist
test: 1080°,5 second/rotation
O R D E R I N G I N F O R M AT I O N
Terminal Strength
H = Inductive
N = Non Inductive
Dielectric
500Volts rms for 1W, 2W 1000Volts rms.
±0.1%
RoHS compliant
Withstanding Voltage 1 minute
High Temperature
Exposure
Exposed to an ambient temperature of 275 ±0.5%
+5/-0°C for 250 ±8 hours,
� ꢀ ꢁ ꢂ ꢃ ꢄ ꢅ ꢆ ꢇ ꢈ
Moisture Resistance MIL-STD-202 Method 106, 7b not applicable ±0.2%
Low Temperature
Storage
Vibration, High
Frequency
Series Power Ohms Tolerance Package
Cold chamber at a temperature of -65 ±2°C ±0.2%
for 24+/-4 hours
Frequency varied 10 to 2000Hz, 200G peak, ±0.1%
2 directions 6 hours each
A = 0.5
B = 1
F = 1%
J = 5%
T = Tape
blank = 25pc Pack
C = 2
K E Y T O F I V E - B A N D C O D E
Load Life
1000/2000 hours at rated power, +25°C, 1.5 ±0.5%
hours “On”, 0.5 hours “Off”
Band
1
2
Digit
0
3
4
5
�ꢁꢂꢃ
ꢀ
Color
Multiplier
Tolerance
S TA N D A R D P A R T N U M B E R S F O R W H / W N S E R I E S
Black
Brown
Red
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
x
1Ω
10Ω
Wattage: 0.5
Series:
0.5
WNA
1.0
WHB
1.0
WNB
2.0
WHC
2.0
1
x
x
x
x
±
±
1% (F)
2% (G)
WHA
WNC
2
100Ω
1KΩ
Ohms
Orange
Yellow
Green
Blue
3
0.1
WHAR10FE WNAR10FE
WHAR25FE WNAR25FE
WHAR50FE WNAR50FE
WHAR75FE WNAR75FE
WHBR10FE
WHBR25FE
WHBR50FE
WHBR75FE
WNBR10FE
WNBR25FE
WNBR50FE
WNBR75FE
WHCR10FE
WHCR25FE
WHCR50FE
WHCR75FE
WNCR10FE
WNCR25FE
WNCR50FE
WNCR75FE
4
10KΩ
0.25
0.50
0.75
5
x 100KΩ
±
0.5% (D)
6
x
x
1MΩ
± 0.25% (C)
± 0.10% (B)
± 0.05%
1
2
4
5
WHA1R0FE WNA1R0FE
WHA2R0FE WNA2R0FE
WHA4R0FE WNA4R0FE
WHA5R0FE WNA5R0FE
WHB1R0FE
WHB2R0FE
WHB4R0FE
WHB5R0FE
WNB1R0FE
WNB2R0FE
WNB4R0FE
WNB5R0FE
WHC1R0FE
WHC2R0FE
WHC4R0FE
WHC5R0FE
WNC1R0FE
WNC2R0FE
WNC4R0FE
WNC5R0FE
Violet
Grey
7
10MΩ
8
White
Gold
9
10
15
25
51
WHA10RFE WNA10RFE
WHA15RFE WNA15RFE
WHA25RFE WNA25RFE
WHA51RFE WNA51RFE
WHB10RFE
WHB15RFE
WHB25RFE
WHB51RFE
WNB10RFE
WNB15RFE
WNB25RFE
WNB51RFE
WHC10RFE
WHC15RFE
WHC25RFE
WHC51RFE
WNC10RFE
WNC15RFE
WNC25RFE
WNC51RFE
x
x
0.1Ω
±
±
5% (J)
Silver
0.01Ω
10% (K)
75
WHA75RFE WNA75RFE
WHA100FE WNA100FE
WHA150FE WNA150FE
WHA200FE WNA200FE
WHB75RFE
WHB100FE
WHB150FE
WHB200FE
WNB75RFE
WNB100FE
WNB150FE
WNB200FE
WHC75RFE
WHC100FE
WHC150FE
WHC200FE
WNC75RFE
WNC100FE
WNC150FE
WNC200FE
100
150
200
250
330
470
560
WHA250FE WNA250FE
WHA330FE
WHB250FE
WHB330FE
WHB470FE
WHB560FE
WNB250FE
WNB330FE
WNB470FE
WNB560FE
WHC250FE
WHC330FE
WHC470FE
WHC560FE
WNC250FE
WNC330FE
WNC470FE
WNC560FE
WHA470FE
WHA560FE
750
1K
2.5K
WHA750FE
WHA1K0FE
WHB750FE
WHB1K0FE
WHB2K5FE
WNB750FE
WNB1K0FE
WHC750FE
WHC1K0FE
WHC2K5FE
WNC750FE
WNC1K0FE
Check product availability at www.ohmite.com
Ohmite Mfg. Co. 1600 Golf Rd., Rolling Meadows, IL 60008 • 1-866-9-OHMITE • Int’l 1-847-258-0300 • Fax 1-847-574-7522 • www.ohmite.com • info@ohmite.com
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