General Note
IRC reserves the right to make changes in product specifi cation without notice or liability.
All information is subject to IRC’s own data and is considered accurate at time of going to print. A subsidiary of
TT electronics plc
• 4222 South Staples Street • Corpus Christi Texas 78411 USA
Wire and Film Technologies Division
Telephone: 361 992 7900 • Facsimile: 361 992 3377 • Website: www.irctt.com
Low Resistance
Metal Element Resistor
Environmental Testing
LOB Series
• Low TCR
• High stability over life
• Tolerances from ±1% to ±5%
• Ultra low resistance values (0.005 Ω to 0.1 Ω)
• Inherently non-inductive (≤.02 µh @ 0.5 MHz)
• Available in 1W, 3W, and 5W rated packages
• Lead free RoHS compliant construction available
Test Parameters MIL-STD 202 MAX %ΔR * Unit
Load Life (2,000 hours) Method 108 ±1% %ΔR
Thermal Shock Method 107 ±1% %ΔR
Vibration Method 204 ±0.5% %ΔR
Mechanical Shock Method 213 ±0.5% %ΔR
Dielectric Strength Method 301 ±0.5% @1000 VAC %ΔR
Insulation Resistance Method 302 >1010@ 100 VDC Ohms
DESCRIPTION:
The LOB Series power precision metal element resistors feature resistance values down to 0.005 with virtually no inductance.
Available in 1, 3, and 5 watt rated axial leaded packages, these resistors are compatible with automatic insertion equipment.
APPLICATIONS:
• Switchmode and linear power supplies
• Automotive current-sensing circuits
• Instrumentation
• Regulators
CONSTRUCTION:
The LOBΩ Series resistors feature tinned copper leads welded directly to a low-temperature coeffi cient resistance element in a
highly automated proprietary process. The leaded resistor elements are then encapsulated in a molding compound.
Specifi cations
*±0.0005 ohm allowance for test/contact error.
*Power Dissipation - The maximum wattage rating depends upon the amount of heat which can be transferred to the surroundings while not exceeding the maximum element temperature. Ambient
air temperature, velocity of cooling air, thermal resistance of heat, and the temperature of surrounding objects will affect this transfer, and must be taken into account when selecting a resistor.
Style Continuous Power Dissipation
@ 25°C in free air (watts)
Overload Power
for 5 seconds (watts)
Maximum Working
Voltage (volts)
Maximum Storage
Temperature (°C)
LOB-1 1 5 1 x R 175
LOB-3 3 15 3 x R 175
LOB-5 5 25 5 x R 175
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LOB Series Issue December 2009 Sheet 1 of 3