0.2 mOhms ±1% 9W Chip Resistor Nonstandard Anti-Sulfur, Automotive AEC-Q200, Current Sense, Moisture Resistant, Pulse Withstanding Metal Element
The WSLP3921L2000FEA is a power metal strip current sense resistor manufactured by Vishay Dale, designed specifically for precision current measurement applications in power electronics circuits. It belongs to the WSL/WSLP family, a line of low-resistance, high-power surface-mount resistors built using a metal strip element rather than conventional thick-film or thin-film resistive technology, giving it characteristics that are particularly well suited to current sensing rather than general-purpose resistive applications.
The defining characteristic of this component is its very low resistance value, which allows it to be placed in series with a current path while introducing minimal voltage drop and power loss, while still producing a measurable voltage signal proportional to the current flowing through it. This voltage signal can then be read by current-sense amplifiers, comparators, or analog-to-digital converters to provide accurate real-time current feedback for power supply regulation, overcurrent protection, battery management, motor control, and similar applications where knowing the instantaneous current is essential to safe and efficient operation.
The metal strip construction used in this series offers a low temperature coefficient of resistance compared to thick-film alternatives, meaning the resistor's value remains more stable across varying operating temperatures, which directly improves the accuracy of current measurements taken over a wide thermal range. The element is also engineered for low thermal EMF and minimal self-inductance, both of which are important for maintaining measurement fidelity in fast-switching power conversion circuits where parasitic effects can otherwise distort the sensed signal.
This particular part is qualified to automotive component reliability standards, reflecting its suitability for use in vehicle electrical systems, battery packs, and other safety- or reliability-critical power applications where component robustness under thermal cycling, vibration, and long-term stress must be assured. The device also features moisture-resistant and pulse-withstanding construction, along with a nonstandard anti-sulfuration design intended to resist corrosion-related resistance drift that can occur in resistors exposed to sulfur-containing environmental contaminants over time, a known failure mode in some conventional thick-film resistor technologies. The component is housed in a surface-mount package and is supplied on tape-and-reel packaging suitable for automated assembly, with construction compliant to RoHS material restrictions.
Spec Sheet
Identification
Part Number: WSLP3921L2000FEA
Series: WSLP
Manufacturer: Vishay Dale
Functional Classification
Device Type: Current sense resistor
Construction: Power metal strip element
Application Role: Series current-sensing element for analog current measurement
Electrical Characteristics
Resistance Value: Ultra-low resistance class, optimized for current sensing
Resistance Tolerance: Tight tolerance class for measurement accuracy
Power Rating: High power dissipation class for its footprint
Temperature Coefficient of Resistance: Low TCR for stable measurement across temperature
Thermal EMF: Low thermal EMF construction
Self-Inductance: Low parasitic inductance, suited to fast-switching circuits
Reliability & Environmental Features
Anti-Sulfuration: Nonstandard anti-sulfur construction for corrosion resistance
Moisture Resistance: Moisture-resistant build
Pulse Withstanding: Rated for pulse-load withstanding capability
Automotive Qualification: AEC-Q200 qualified
RoHS Compliance: Yes
Mechanical Specifications
Case Size Class: 3921 surface-mount footprint
Mounting Method: Surface mount technology (SMT)
Terminal Construction: Metal strip element with welded or clad terminations per series design
Packaging
Packaging Format: Tape-and-reel
Packaging Code Meaning: Suffix denotes lead-free, standard reel quantity packaging