The **LR1148L-AD-AF5-R** is a specific low-dropout (LDO) linear regulator manufactured by **UTC (Unisonic Technologies)**. It is designed to provide a stable, adjustable output voltage for low-power electronic circuits. --- ### 1. Part Number Breakdown Understanding the suffix codes helps identify the physical and electrical characteristics of the component: | Part Segment | Meaning | Details | | :--- | :--- | :--- | | **LR1148** | Model Series | 1A Low Dropout Linear Regulator | | **L** | Halogen Free | Lead-free and Green packaging | | **AD** | Adjustable | The output voltage is set via external resistors | | **AF5** | Package Code | SOT-25 (also known as SOT-23-5) | | **R** | Tape & Reel | Packaging method for automated assembly | --- ### 2. Key Technical Specifications The LR1148 is favored in battery-powered applications due to its high accuracy and low quiescent current. | Parameter | Specification | | :--- | :--- | | **Input Voltage Range** | 2.5V to 6.0V | | **Output Voltage Range** | 1.2V to 5.0V (Adjustable) | | **Max Output Current** | 1.0A (1000mA) | | **Dropout Voltage** | ~300mV @ 1A (Typical) | | **Quiescent Current** | ~50µA | | **Operating Temp** | -40°C to +85°C | --- ### 3. Pin Configuration (SOT-25) In the AF5 (SOT-25) package, the pins are typically assigned as follows: 1. **VIN**: Input Voltage. 2. **GND**: Ground. 3. **EN (CE)**: Chip Enable (High = On, Low = Shutdown). 4. **ADJ (FB)**: Feedback pin used to set output voltage. 5. **VOUT**: Regulated Output Voltage. --- ### 4. Features and Applications #### Features: * **Low Dropout:** Allows the device to operate even when the input voltage is very close to the output voltage. * **Enable Pin:** Includes a shutdown mode to conserve battery life (draws < 1µA when disabled). * **Built-in Protection:** Includes thermal shutdown and current limit protection. #### Common Applications: * Portable battery-powered equipment (Smartphones, Tablets). * Wireless LAN (WLAN) cards and Bluetooth modules. * Low-voltage microcontrollers and FPGA power rails. * Camera modules. --- ### 5. Standard Circuit Example To set the output voltage ($V_{out}$), you use a voltage divider on the **ADJ** pin. The formula is generally: `Vout = Vref * (1 + R1 / R2)` *(Where $V_{ref}$ is typically 0.8V for this series).*