The **CMF-RQ50** series is a specialized line of high-power, surface-mount (SMD) thick film power resistors manufactured by Bourns. These components are primarily used for current sensing and circuit protection in automotive and industrial applications. --- ### ## Technical Specifications The CMF-RQ50 series is characterized by its robust design and high reliability. Below are the core electronic parameters: | Parameter | Value / Range | | :--- | :--- | | **Resistance Range** | 0.010 Ω to 0.500 Ω | | **Power Rating** | 0.5 Watts to 1.5 Watts (depending on configuration) | | **Tolerance** | ±1.0% (Standard) | | **Temperature Coefficient (TCR)** | ±100 ppm/°C | | **Operating Temperature** | -55 °C to +155 °C | | **Package Size** | 1206 (3216 Metric) | --- ### ## Key Electronic Features 1. **Thick Film Technology**: The resistor uses a metal-glaze resistive element fired onto a high-quality ceramic substrate. This provides a balance between cost-efficiency and power density. 2. **Automotive Grade (AEC-Q200)**: These parts are AEC-Q200 compliant, meaning they are tested for high-stress environments including thermal shock, moisture resistance, and mechanical vibration. 3. **Low Resistance Values**: Because the resistance is very low (milli-ohms), it is ideal for **current sensing**. Designers measure the voltage drop across the component to calculate the current flowing through a circuit ($I = V/R$). 4. **Sulfur Resistance**: Many versions of this series are designed to be "anti-sulfur," preventing corrosion of the silver internal terminals when exposed to harsh industrial atmospheres. --- ### ## Common Applications The CMF-RQ50 series is found in power management systems where monitoring current is critical: * **BMS (Battery Management Systems)**: Tracking charge/discharge cycles in EV batteries. * **DC-DC Converters**: Regulating output current in power supplies. * **Motor Control**: Monitoring phase current in brushless DC motors. * **LED Drivers**: Ensuring constant current for high-brightness lighting. --- ### ## Termination and Mounting These parts feature **wrap-around terminations** with a nickel barrier and a tin (Sn) finish, making them compatible with standard reflow soldering processes. The 1206 footprint allows for high power dissipation without occupying excessive PCB real estate.