The **78L12ML-T92-R** is a specific variant of the 78L12 series, which is a popular 3-terminal positive fixed voltage regulator. This component is designed to provide a stable 12V output from a higher DC input voltage. --- ### 1. Part Number Breakdown The suffixing on these components often refers to the package type and the manufacturer's internal coding (typically Unisonic Technologies - UTC). | Code Segment | Meaning | | :--- | :--- | | **78** | Positive Voltage Regulator family | | **L** | Low current (typically 100mA max) | | **12** | Output Voltage (12 Volts) | | **ML** | High-precision/Manufacturer specific tolerance code | | **T92** | Package Type (TO-92) | | **R** | Tape and Reel (Packaging method) | --- ### 2. Technical Specifications The 78L12 is the "little brother" of the 7812. While the 7812 handles 1A to 1.5A, the **L** version is for low-power applications. | Parameter | Typical Value | | :--- | :--- | | **Output Voltage** | +12V DC | | **Input Voltage (Min)** | 14.5V DC (Required for proper regulation) | | **Input Voltage (Max)** | 30V - 35V DC | | **Max Output Current** | 100mA (0.1A) | | **Quiescent Current** | 3mA to 5mA | | **Operating Temp Range** | -40°C to +125°C | | **Package** | TO-92 (Plastic, 3-pin) | --- ### 3. Pinout Configuration In the TO-92 package, looking at the flat side with the pins pointing down: 1. **Pin 1: Output** (Regulated +12V) 2. **Pin 2: Ground** (Common) 3. **Pin 3: Input** (Unregulated DC voltage) --- ### 4. Typical Application Circuit To ensure stability and reduce noise, capacitors are usually placed close to the pins. ```markdown Input (+15V to +30V) ----[ Pin 3 ] [ Pin 1 ]---- Output (+12V) | | [0.33uF Cap] [0.1uF Cap] | | GND ----------------------[ Pin 2 ]------┴----------- GND ``` ### 5. Key Features & Protection * **Internal Thermal Overload Protection:** The device will shut down if it gets too hot. * **Internal Short Circuit Current Limiting:** Protects the device and the power source if the output is shorted. * **No External Components Required:** Except for filtering capacitors, it is a "plug and play" solution for voltage regulation. ---