The **TL431TVG-AE2-R** is a specific variant of the industry-standard TL431 shunt regulator. It is a three-terminal programmable shunt regulator diode that acts like a Zener diode with a much sharper turn-on characteristic and a programmable output voltage. --- ## 1. Technical Specifications This component is designed to provide a stable voltage reference for various electronic circuits. Below are the primary specifications for this specific part: | Parameter | Specification | | :--- | :--- | | **Output Voltage ($V_{ref}$)** | 2.495 V (Typical) | | **Programmable Range** | 2.5 V to 36 V | | **Output Current ($I_{ka}$)** | 1.0 mA to 100 mA | | **Temperature Stability** | 50 ppm/°C (Typical) | | **Operating Temperature** | -40°C to +125°C | | **Package Type** | SOT-23-3 (Typical for AE2 suffix) | | **Manufacturer** | UTC (Unisonic Technologies) | --- ## 2. Pin Configuration The device features three functional pins. In a standard SOT-23 package, the layout is usually: 1. **Reference ($R$):** Used to set the output voltage via a voltage divider. 2. **Cathode ($K$):** The positive terminal (similar to a Zener cathode). 3. **Anode ($A$):** The common ground terminal. --- ## 3. Key Features and Operation * **Adjustable Output:** By using two external resistors, the output voltage can be set to any value between $V_{ref}$ (2.5V) and 36V. The formula used is: $$V_{out} = V_{ref} \times (1 + \frac{R1}{R2})$$ * **Low Dynamic Impedance:** It has a typical output impedance of 0.22 $\Omega$, making it far superior to standard Zener diodes for regulation. * **Sink Current Capability:** It can sink up to 100mA, allowing it to drive optocouplers or small transistors directly. --- ## 4. Typical Applications The TL431 series is one of the most versatile components in power electronics: * **Switch Mode Power Supplies (SMPS):** Used in the feedback loop (paired with an optocoupler) to regulate the output voltage. * **Voltage Monitoring:** Acting as a comparator to trigger an alarm or shutdown if voltage exceeds a threshold. * **Precision Current Limiter:** When combined with a transistor, it can create a highly accurate constant current source. * **Zener Diode Replacement:** Used where a precise, non-standard Zener voltage is required. ---