The **LR1102BL-18-AF5-R** is a low-dropout (LDO) linear regulator produced by Unisonic Technologies (UTC). It is designed specifically for low-power applications requiring a stable voltage supply. ### 1. Part Number Breakdown Understanding the nomenclature helps identify the specific characteristics of the component: | Code Segment | Meaning | | :--- | :--- | | **LR1102** | Base series number (LDO Linear Regulator) | | **B** | Indicates the accuracy/version of the IC | | **L** | Lead-free and Halogen-free (Environmental Compliance) | | **18** | Fixed Output Voltage: **1.8V** | | **AF5** | Package Type: **SOT-25** | | **R** | Packing style: **Tape & Reel** | --- ### 2. Key Technical Specifications The LR1102 series is characterized by high precision and low quiescent current. | Parameter | Specification | | :--- | :--- | | **Output Voltage** | 1.8V (Fixed) | | **Maximum Output Current** | 300mA | | **Input Voltage Range** | Up to 6V (Typical) | | **Quiescent Current ($I_Q$)** | ~50µA (Typical) | | **Dropout Voltage** | ~300mV @ 300mA | | **Ripple Rejection (PSRR)** | 70dB @ 1kHz | | **Operating Temperature** | -40°C to +85°C | --- ### 3. Pin Configuration (SOT-25) The AF5 (SOT-25) package typically follows this standard layout for LDOs: 1. **VIN**: Input Supply Voltage. 2. **GND**: Ground pin. 3. **CE (Enable)**: High = On; Low = Shutdown mode. 4. **NC/BP**: No connection or Bypass capacitor (used to reduce noise). 5. **VOUT**: Regulated 1.8V Output. --- ### 4. Features & Protective Functions * **Low Noise:** Optimized for RF and sensitive analog circuits. * **Shutdown Mode:** Includes a chip-enable (CE) pin to reduce power consumption to near zero when the device is not in use. * **Built-in Protection:** * **Current Limit Protection:** Prevents damage during short-circuit conditions. * **Thermal Shutdown:** Automatically turns off the IC if the junction temperature exceeds safe limits. ### 5. Common Applications * Battery-powered equipment (Mobile phones, tablets). * Low-voltage microcontrollers (MCUs) requiring a 1.8V core voltage. * Reference voltage sources for analog-to-digital converters (ADCs). * Wireless communication modules (Bluetooth/Zigbee).