## Technical Overview: BAS21G-CB2-R The **BAS21G-CB2-R** is a high-voltage, high-speed switching diode designed in a surface-mount package. It is primarily used in industrial and consumer electronics for circuit protection and signal switching. --- ### 1. Key Technical Specifications Below are the critical electrical parameters for the BAS21G-CB2-R: | Parameter | Symbol | Value | Unit | | :--- | :--- | :--- | :--- | | **Repetitive Peak Reverse Voltage** | $V_{RRM}$ | 250 | V | | **Continuous Forward Current** | $I_F$ | 200 | mA | | **Forward Voltage Drop** (at $I_F = 100mA$) | $V_F$ | 1.0 (max) | V | | **Reverse Recovery Time** | $t_{rr}$ | 50 | ns | | **Reverse Leakage Current** (at $V_R = 200V$) | $I_R$ | 100 | nA | | **Operating Temperature** | $T_j$ | -55 to +150 | °C | --- ### 2. Functional Characteristics * **High Voltage Rating:** With a 250V rating, it is suitable for applications involving higher voltage rails than standard small-signal diodes (which typically top out at 75V-100V). * **Fast Switching:** The 50ns recovery time allows it to be used in high-frequency switching circuits without significant power loss. * **Small Footprint:** Typically housed in a **SOD-323** or **SOT-23** package (depending on the specific manufacturer variant denoted by the suffix), making it ideal for space-constrained PCB designs. * **Green/Halogen Free:** The "G" in the part number often signifies "Green" or Halogen-free materials, complying with modern environmental standards (RoHS). --- ### 3. Applications The BAS21 series is versatile and commonly found in: 1. **General Purpose Switching:** Turning signals on and off rapidly. 2. **Reverse Polarity Protection:** Protecting sensitive low-current components from accidental battery reversal. 3. **Clamping & Clipping:** Limiting voltage spikes in inductive loads (like small relays). 4. **AC-DC Rectification:** Small scale rectification for auxiliary power supplies. --- ### 4. Circuit Symbol and Pinout In a standard schematic, the BAS21 follows the standard diode representation: ```text Anode (1) Cathode (2) +-------|>|-------+ ``` * **Pin 1 (Anode):** Current enters. * **Pin 2 (Cathode):** Current exits (marked with a band on the physical component). ---