The **79D07AL-TM3-R** is a specific part number for a **Negative Voltage Regulator**. It is commonly manufactured by UTC (Unisonic Technologies Co., Ltd). Below is a detailed breakdown of its electronic characteristics and specifications. --- ### 1. General Overview The 79D07 series consists of three-terminal negative voltage regulators. They are designed to provide a fixed negative output voltage and are often used in dual-supply circuits (complementary to the 78xx series). ### 2. Technical Specifications The "07" in the part number indicates a fixed output of **-7 Volts**. | Feature | Specification | | :--- | :--- | | **Output Voltage** | -7.0 V | | **Output Current** | Up to 0.5 A (500mA) | | **Input Voltage (Max)** | -25 V to -35 V | | **Operating Temperature** | -40°C to +125°C | | **Package Type** | TO-251 (indicated by TM3 code) | | **Polarity** | Negative | --- ### 3. Part Number Decoder Understanding the suffixes helps in identifying the physical and environmental properties: * **79D**: Series identifier (Negative Voltage Regulator, Medium Current). * **07**: Output Voltage (-7V). * **AL**: Denotes high accuracy or specific lead-free plating (varies by manufacturer revision). * **TM3**: Refers to the **TO-251** package (also known as I-PAK). This is a through-hole package similar to D-PAK but with straight leads. * **R**: Tape and Reel or specific RoHS compliance/packaging style. --- ### 4. Key Protection Features The 79D07AL includes several internal protection circuits to ensure stability and safety: 1. **Thermal Overload Protection**: Shuts down the device if the internal temperature exceeds limits. 2. **Short Circuit Current Limiting**: Restricts the output current if the output is shorted to ground. 3. **Safe-Area Compensation**: Adjusts the output based on the voltage-current operating conditions. ### 5. Common Applications * **Dual Power Supplies**: Working alongside a 7807 to provide ±7V rails for Operational Amplifiers (Op-Amps). * **Audio Equipment**: Providing clean negative bias for pre-amplification stages. * **Industrial Controls**: Negative logic supply for specific sensors. --- ### 6. Typical Circuit Implementation ```text Input (-Vin) ----[ 79D07 ]---- Output (-7V) | Ground ``` *Note: Unlike positive regulators, the input and output capacitors are critical for stability. Typically, a 2.2µF tantalum or 10µF aluminum electrolytic capacitor is used on the input, and a 1µF capacitor on the output.*