TT Electronics OARS Surface Mount Current Sense Resistors

TT Electronics OARS surface mount current sense resistors are ideal for measuring currents up to 70A. Their open-air format gives both mechanical flexibility and thermal isolation between the element and the PCB, features lacking in flat chip formats. The flexibility of the terminations makes these able to withstand thermal cycling and board flexing with minimal stress on the solder joints. The thermal isolation means that the shunt does not dump heat into the PCB. 

OARS parts consist of copper terminations welded to a resistance alloy strip which is then cut and formed. Available in numerous standard values, ohmic value adjustment is achieved mainly by control of element width, with fine trimming achieved with a side notch of no more than 1mm depth. This results in a robust, low-inductance part that can withstand high current surges. An all-copper zero ohm jumper version is also available.

Features

• AEC-Q200 qualified
• Enhances reliability by avoiding heating of the PCB
• Flexible leads for thermal expansion
  
• Frees up PCB real estate between terminations
• Inductance below 10nH
• Open-air design separates hot spot from solder joints
  
• Operating temperature from -55 to +160°C
  
• Power ratings of 1, 3 and 5 W @70°C
  
• Resistance tolerances 1% and 5%
• Resistance values from 1 to 50 milliohms
  
• TCR to +/-40ppm/°C
• Zero-ohm 65A jumper version

Applications

• All applications that require measurement of the flow of current in electronic systems
• Automotive body control
• Battery chargers
• Battery-powered equipment
  
• Electrical actuator control
• Industrial control systems
• Power supply current limiting
• Small motor stall monitoring

Technical Specifications