Current Sensing Resistor

The Current Sensing Resistor from RST Electric provides a high-accuracy, low-loss solution for sensing currents in applications requiring 1W to 3W power dissipation – a common requirement in battery management, portable electronics, and industrial control loops. This Low Ohm Resistor utilizes a precision metal alloy element (manganin or similar) that offers an exceptional combination of low temperature coefficient (±50 to ±100 ppm/°C), high surge capability, and long-term stability. The vertical, radial-lead package is optimized for minimal PCB footprint, with a body height of just 4.5mm, making it suitable for slim devices where height clearance is a constraint.

Product Features

The construction of this Current Sensing Resistor emphasizes both electrical precision and mechanical robustness. The resistive element is fabricated from a high-stability alloy, then welded to tinned copper leads and encapsulated in a flame-retardant coating that provides protection while allowing efficient heat dissipation. The open-air design, combined with the low resistance values (3mΩ to 100mΩ), results in minimal self-heating and virtually zero inductance – critical for preserving signal integrity in high-frequency switching circuits and fast transient sensing applications.

Related Series

The FLQ50 series offers three standard power ratings (1W, 2W, 3W), each covering a resistance range from 3mΩ to 100mΩ. This broad range allows designers to select the optimal voltage drop (typically 50mV to 300mV at full scale) for direct interfacing with analog-to-digital converters and operational amplifiers. Standard tolerances of ±1%, ±2%, ±5%, and ±10% accommodate both precision measurement and general-purpose applications. As a trusted Current Sense Resistor manufacturer in China, RST Electric combines over 10 years of precision resistor engineering with rigorous quality control to deliver components that provide stable, drift-free current feedback in the most demanding environments.

Technical Specification

Product Details of Current Sensing Resistor

1.Optimized for 1W–3W Power Range – Specifically designed for low-to-medium power sensing applications common in battery-powered and portable devices.

2.Ultra-Low Resistance Values – From 3mΩ to 100mΩ, enabling accurate current measurement with minimal power loss and voltage drop.

3.Exceptional Temperature Stability – Low TCR (±20 ppm/°C to ±100 ppm/°C) ensures minimal resistance drift across operating temperature range, critical for precision measurement.

4.Ultra-Low Inductance – Metal alloy construction virtually eliminates parasitic inductance, preserving signal integrity in high-frequency switching circuits.

5.Slim Profile Design – Body height of just 4.5mm allows mounting in space-constrained enclosures and low-profile devices.

6.Flexible Lead Spacing – Customizable lead spacing from 10mm to 25mm accommodates various PCB hole patterns and layout requirements.

7.Precision Tolerances – Available in ±1%, ±2%, ±5%, and ±10% to meet both high-accuracy and cost-sensitive design goals.

8.High Stability & Reliability – Precision metal alloy element offers excellent long-term stability and resistance to thermal cycling.

9.Flame-Retardant Coating – Encapsulated in a durable, flame-retardant material that meets safety requirements for industrial and consumer electronics.

10.Customizable Parameters – Special resistance values, lead forming, and matched pairs available for application-specific requirements.

Product Applications

Drawing and dimensions

How to Package Current Sensing Resistor？

● Bulk Packaging: Resistors are packed in anti-static bags with foam padding, then placed in corrugated cartons to prevent lead bending and element deformation.

● Lead Protection: Leads are kept straight with foam end caps or plastic lead-forming spacers.

● Documentation: Packing lists and inspection certificates included with each shipment.

● Freight Options: Express courier (DHL/FedEx/UPS) for small quantities, air freight for medium volumes, sea freight for bulk orders.

Maintenance Guide

Daily Use Maintenance: Operate strictly within the rated parameters, avoid overloading and operating beyond the specified range, and prevent the burning of metal alloy components; avoid leaving the Current Sensing Resistor in an environment below -55℃ or above 85℃ for an extended period, to prevent resistance value drift and affect the detection accuracy.

Cleaning Maintenance: Regularly wipe the surface dust of the resistor with a dry soft cloth. Do not use corrosive cleaners to avoid damaging the flame-retardant coating and metal components; before cleaning, cut off the power supply and wait for the resistor to cool completely before operating to prevent short circuits.

Lead Wire Maintenance: Avoid pulling or bending the lead wires to prevent the soldering points from falling off; if you find that the lead wires are oxidized or loose, handle them promptly to avoid contact problems that may cause detection errors.

Storage Maintenance: When not in use, store the resistor in a dry, ventilated, and static-free environment, away from damp and hot areas to prevent the components from getting damp, oxidized, and shorten the service life.