The **LR1102AG-27-AF5-R** is a low-dropout (LDO) linear voltage regulator manufactured by UTC (Unisonic Technologies Co., Ltd). It is designed to provide a stable fixed output voltage with high precision and low noise. --- ### 1. Key Technical Specifications The following table summarizes the primary electrical characteristics of the LR1102AG-27-AF5-R: | Feature | Specification | | :--- | :--- | | **Output Voltage** | 2.7V (Fixed) | | **Input Voltage Range** | Up to 6.0V | | **Maximum Output Current** | 300mA | | **Dropout Voltage** | Low (Typ. 200mV @ 100mA) | | **Package Type** | SOT-25 / SOT-23-5 (AF5) | | **Quiescent Current** | ~50µA | | **Operating Temperature** | -40°C to +85°C | --- ### 2. Part Number Breakdown Understanding the nomenclature helps identify specific features of this variant: * **LR1102**: Base series name (High-speed LDO). * **A**: Accuracy / Version identifier (usually ±2%). * **G**: Halogen-free and RoHS compliant (Green). * **27**: Fixed Output Voltage of **2.7V**. * **AF5**: Package code for **SOT-25** (also known as SOT-23-5). * **R**: Tape and Reel packaging. --- ### 3. Pin Configuration (SOT-25) Standard pinout for this regulator type: 1. **VIN**: Input Voltage Supply. 2. **GND**: Ground Reference. 3. **CE (or EN)**: Chip Enable (Active High). If pulled low, the device enters standby mode. 4. **NC / BP**: No Connection or Bypass (often used for a noise-reduction capacitor). 5. **VOUT**: Regulated Output Voltage (2.7V). --- ### 4. Core Features and Applications #### Features: - **Low Dropout:** Ensures the device can regulate 2.7V even when the input voltage is only slightly higher (e.g., 2.9V). - **Built-in Protection:** Includes thermal shutdown and current limiting to prevent damage during fault conditions. - **Enable Function:** Allows the system to turn off the regulator to save power in battery-operated devices. #### Common Applications: - **Battery-powered equipment:** Cell phones, PDAs, and handheld scanners. - **Low-voltage logic:** Providing stable rails for microcontrollers (MCUs) or RF modules requiring exactly 2.7V. - **Noise-sensitive circuits:** Due to its linear nature, it provides cleaner power than switching regulators. --- ### 5. Typical Application Circuit ```mermaid graph LR A[Input Vin] --> B(C1: 1uF) B --> C[LR1102AG Pin 1] C --> D[LR1102AG Pin 5] D --> E(C2: 1uF) E --> F[Output 2.7V] G[GND] --- B G --- E ``` *Note: It is recommended to use ceramic capacitors (at least 1µF) at both input and output for stability.*