The **LR1102B-50-AF5-R** is a specific low-dropout (LDO) linear voltage regulator manufactured by **UTC (Unisonic Technologies)**. It is designed to provide a stable, fixed output voltage while maintaining a small footprint, making it ideal for battery-powered or space-constrained electronic devices. --- ## 1. Technical Specifications | Parameter | Specification | | :--- | :--- | | **Output Voltage** | Fixed 5.0V | | **Input Voltage (Max)** | Up to 7.0V | | **Output Current** | 300mA | | **Package Type** | SOT-25 (also known as SOT-23-5) | | **Quiescent Current** | ~50µA (Typical) | | **Drop-out Voltage** | ~300mV @ 300mA | | **Operating Temperature** | -40°C to +85°C | --- ## 2. Key Features and Functions * **Low Dropout (LDO):** It can maintain a stable 5V output even when the input voltage is only slightly higher (e.g., 5.3V), which minimizes energy loss as heat. * **Built-in Protection:** * **Current Limiting:** Protects the IC during short-circuit conditions. * **Thermal Shutdown:** Shuts the device off if it exceeds safe operating temperatures. * **Enable Pin:** Includes an "ON/OFF" control pin, allowing the system to put the regulator into standby mode to save battery life. * **Low Noise:** Designed to provide a clean power supply for sensitive analog or RF components. --- ## 3. Pin Configuration (SOT-25) The standard pinout for this UTC part is typically as follows: | Pin Number | Name | Description | | :--- | :--- | :--- | | 1 | **VIN** | Input Supply Voltage | | 2 | **GND** | Ground | | 3 | **CE / EN** | Chip Enable (High = ON, Low = OFF) | | 4 | **NC / BYP** | No connection or Bypass Capacitor | | 5 | **VOUT** | Regulated 5.0V Output | --- ## 4. Typical Application Circuit To ensure stability, LDOs require external capacitors. Below is a conceptual representation of how to wire the LR1102B: ```text [Input Voltage] ----[ VIN ]-------[ VOUT ]---- [ 5.0V Load ] | | [1uF Cap] [1uF - 10uF Cap] | | [Ground] ------------[ GND ]------------------- [ Ground ] ``` --- ## 5. Part Number Decoding The suffix **"AF5-R"** provides information about the physical packaging: * **AF5:** Indicates the SOT-25 package style. * **R:** Indicates "Tape and Reel" packaging for automated assembly. * **50:** Represents the 5.0V output voltage.