The **78D07G-TM3-R** is a specific part number for a fixed-output linear voltage regulator. It belongs to the 78xx series, which is industry-standard for providing stable DC power. Below is a breakdown of its technical specifications, part number nomenclature, and typical applications. --- ## 1. Technical Specifications The "07" in the part number indicates a fixed output of **7 Volts**. This is a relatively unique voltage compared to the more common 5V or 12V regulators. | Parameter | Value | | :--- | :--- | | **Output Voltage** | +7V DC | | **Max Input Voltage** | 25V - 30V DC | | **Output Current** | Up to 1.0A (depending on heat sinking) | | **Package Type** | TO-252 (DPAK) | | **Dropout Voltage** | ~2.0V (Standard Linear) | | **Operating Temperature** | -40°C to +125°C | --- ## 2. Part Number Breakdown (UTC/Unisonic) The part number follows the naming convention of manufacturers like UTC (Unisonic Technologies Co.): * **78**: Positive voltage regulator family. * **D**: Often denotes the current rating or specific design variant (usually 1A class). * **07**: Fixed output voltage (7.0 Volts). * **G**: Halogen-free and RoHS compliant (Green). * **TM3**: Package code (typically refers to the **TO-252** / DPAK surface mount package). * **R**: Tape and Reel packaging. --- ## 3. Pinout Configuration Since it is in a TO-252 (DPAK) package, the pinout is standard for the 78 series: 1. **Pin 1 (Input):** Unregulated DC input voltage. 2. **Pin 2/Tab (Ground):** Common ground for both input and output. 3. **Pin 3 (Output):** Regulated +7V output. --- ## 4. Key Features & Circuit Requirements * **Internal Protection:** Includes internal current limiting, thermal shutdown, and safe-area compensation, making it nearly "indestructible" under normal overload conditions. * **Heat Dissipation:** As a linear regulator, it dissipates excess voltage as heat. Formula: $P = (V_{in} - V_{out}) \times I_{out}$. * **Required Capacitors:** * **Input ($C_{in}$):** A 0.33µF ceramic or tantalum capacitor is required if the regulator is far from the power supply filter. * **Output ($C_{out}$):** A 0.1µF capacitor is recommended to improve stability and transient response. --- ## 5. Typical Applications * **Pre-regulation:** Providing a stable 7V rail for sensitive analog circuits. * **Logic Systems:** Powering legacy systems or specific sensors that require higher than 5V but lower than 9V. * **On-card Regulation:** Used on PCBs to eliminate noise distribution problems associated with single-point regulation.