Vishay - CSM3637P Current Sensing Resistor Features TCR of 15 ppm/°C Max at Power Ratings to 5 W, 40

The resistance value range for the CSM3637P is 3 mΩ to 100 mΩ. Any as required value (such as 10.2345 mΩ vs. 10 mΩ) is available within that range at no extra charge and with no additional delivery time.

The high 5 W rating of the CSM3637P, which represents a key advance for this device type, is enabled by 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, significantly reducing termination resistance.

A further benefit of the CSM3637P 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 — thus minimizing temperature differentials. 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 CSM3637P 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°C to +125°C (+25°C ref.), and a tolerance of ±0.1%. Its load-life stability represents an approximate five-fold improvement over typical current-sensing resistors, which means better stability for voltage division and precision current sensing applications for switching linear power supplies, power amplifiers, measurement instrumentation, bridge networks, and medical and test equipment.

The low absolute TCR provided by the CSM3637P reduces errors due to temperature changes and thus reduces a major source of uncertainty in current measurement, even for systems that need to work in extremely high temperatures or radiation-rich environments, including down-hole oil exploration and well logging equipment or the deep-sea underwater repeaters used for cross-ocean communications.

The stability of the CSM3637P can be further enhanced by post manufacturing operations (PMOs) expressly developed for Bulk Metal® Foil resistors, which include temperature cycling, short-time overload, and accelerated load life.

Samples and production quantities of the CSM3637P are available now, with lead times of five working days for samples, and six weeks for standard orders.