The **FWP221T2-R002-F** is a high-precision, low-resistance shunt resistor commonly used in power management and current sensing applications. Below is a detailed technical breakdown of its electronic specifications and characteristics. --- ### 1. General Overview This component is a **Metal Plate Current Sense Resistor**. It is designed to measure current by monitoring the voltage drop across it, following Ohm's Law ($V = I \times R$). ### 2. Technical Specifications | Feature | Specification | Details | | :--- | :--- | :--- | | **Resistance Value** | $0.002\, \Omega$ ($2\, m\Omega$) | Extremely low resistance to minimize power loss. | | **Power Rating** | $1W - 2W$ | Typically rated for high power dissipation relative to size. | | **Tolerance** | $\pm 1\%$ (F) | High precision for accurate current measurement. | | **Package Size** | 1206 or 2512 | Often found in surface mount (SMD) standard footprints. | | **Temperature Coefficient** | Low TCR (e.g., $\pm 50 - 100\, ppm/^\circ C$) | Ensures stability across a wide temperature range. | | **Construction** | Metal Alloy / Metal Plate | Robust material capable of handling high surge currents. | --- ### 3. Key Electronic Characteristics #### A. Low Resistance (R002) The "R002" in the part number indicates a resistance of **2 milliohms**. This is critical for: * **Efficiency:** Reducing the amount of energy wasted as heat ($P = I^2R$). * **Sensitivity:** Providing a measurable millivolt signal to a Current Sense Amplifier or MCU. #### B. Metal Plate Technology Unlike standard thick-film resistors, the FWP series uses a solid metal alloy. This provides: * Superior heat dissipation. * High reliability under thermal cycling. * Low inductance, which is vital for high-frequency switching circuits. #### C. Tolerance (F) The suffix **"F"** denotes a **1% tolerance**. This means the actual resistance will be between $0.00198\, \Omega$ and $0.00202\, \Omega$. --- ### 4. Typical Applications The FWP221T2-R002-F is typically integrated into the following circuits: * **Battery Management Systems (BMS):** Monitoring charge and discharge currents in Li-ion packs. * **DC-DC Converters:** Providing feedback for over-current protection (OCP). * **Motor Control:** Detecting the current load on motors for precise speed/torque adjustment. * **Power Supplies:** Serving as a sense element in high-efficiency switch-mode power supplies (SMPS). --- ### 5. Implementation Example (Code Logic) If you are using this resistor with a 10-bit ADC (5V reference) and a gain-of-50 amplifier to measure current: ```python # Constants R_SHUNT = 0.002 # 2mOhm GAIN = 50 V_REF = 5.0 ADC_RESOLUTION = 1024 def calculate_current(adc_value): # Calculate voltage at ADC pin v_out = (adc_value / ADC_RESOLUTION) * V_REF # Calculate voltage across shunt (before gain) v_shunt = v_out / GAIN # Calculate Current (I = V / R) current = v_shunt / R_SHUNT return current # Example: ADC reads 205 print(f"Measured Current: {calculate_current(205):.2f} Amps") ```