The **LR1102BL-28-AF5-R** is a specific part number for a Low Dropout (LDO) linear regulator produced by **UTC (Unisonic Technologies)**. This component is designed to provide a stable, fixed output voltage for low-power electronic circuits. ### 1. Part Number Breakdown The nomenclature reveals the key specifications of the component: | Prefix/Suffix | Meaning | Specification | | :--- | :--- | :--- | | **LR1102** | Base Series | Low Dropout Linear Regulator | | **B** | Version | Specific performance characteristic (internal code) | | **L** | Lead-Free | Halogen-free and RoHS compliant | | **28** | Voltage Code | **2.8V** Fixed Output | | **AF5** | Package Code | **SOT-25** Package | | **R** | Packing | Tape and Reel | --- ### 2. Key Technical Specifications Below are the typical electrical parameters for this device: | Parameter | Value | | :--- | :--- | | **Input Voltage Range** | Up to 6.0V | | **Output Voltage** | 2.8V (Fixed) | | **Output Current** | 300mA (Typical) | | **Dropout Voltage** | Low (typically < 300mV at full load) | | **Quiescent Current** | Low (typically ~50µA) | | **Operating Temperature** | -40°C to +85°C | --- ### 3. Pin Configuration (SOT-25) The SOT-25 package usually follows a standard LDO pinout: 1. **VIN**: Input Voltage. 2. **GND**: Ground. 3. **EN (CE)**: Chip Enable (High = On, Low = Off). 4. **NC/BP**: No Connection or Bypass Capacitor (for noise reduction). 5. **VOUT**: Regulated 2.8V Output. --- ### 4. Features and Applications #### Features * **High PSRR:** Effective at filtering out noise from the power supply. * **Built-in Protection:** Usually includes thermal shutdown and current limit protection. * **Stability:** Designed to be stable with low-ESR ceramic capacitors. #### Applications * **Battery-Powered Equipment:** Smartphones, cameras, and handheld sensors. * **Wireless Modules:** Powering Bluetooth or Wi-Fi chips that require clean 2.8V. * **Post-Regulation:** Cleaning up noisy output from a switching DC-DC converter. --- ### 5. Implementation Example To use this part, a basic circuit requires input and output capacitors for stability. ```c // Typical Hardware Schematic Logic Input Voltage (3.3V - 5.0V) --> [ 1.0uF Capacitor ] --> PIN 1 (VIN) PIN 2 (GND) --> System Ground Enable Signal (High) --------------------------------> PIN 3 (EN) PIN 5 (VOUT) --> [ 1.0uF Capacitor ] --> 2.8V Load ```