Vishay CSM3637P current sensing resistor

Vishay has released the CSM3637P, a low-value current sense resistor with an improved power rating of 5 W, maximum current handling up to 40 A and an absolute TCR of ±15 ppm/°C maximum.

The resistance value range for the CSM3637P is 3 to 100 mΩ. Any ‘as required’ value (such as 10.2345 mΩ vs 10 mΩ) is available within that range.

The 5 W rating is possible because of the installed heat sink on top of the resistive element, allowing better heat dissipation. The four-terminal device is also designed with its current leads separated from the voltage sensing leads, reducing termination resistance.

A further benefit is its low thermal EMF of less than 3 µV/°C, enabled by a design in which the welded terminals make intimate contact with the chip. This construction reduces the ‘battery effect’ or parasitic voltage exhibited by most current-sensing resistors, while protecting pure current-to-voltage conversion from such interference in DC applications.

The resistor range features an improved load-life stability of ±0.2% at +70°C for 2000 h at rated power, an absolute TCR of ±15 ppm/°C from -55 to +125°C (+25°C ref) and a tolerance of ±0.1%.