The **LR1801L-15-SH2-R** is a Low Dropout (LDO) Linear Regulator manufactured by UTC (Unisonic Technologies). It is designed to provide a stable, fixed output voltage from a higher input voltage with very low power dissipation. ### 1. Technical Specifications Below are the primary electrical characteristics for this specific part number: | Parameter | Specification | | :--- | :--- | | **Output Voltage (Fixed)** | 1.5V | | **Input Voltage Range** | Up to 10V (Max 12V absolute) | | **Output Current** | 1.0A (Typical) | | **Dropout Voltage** | ~0.4V @ 1A | | **Quiescent Current** | ~50µA | | **Package Type** | SOT-263 / SOT-23 / HSOP-8 (Part suffix "SH2" indicates **SOT-263**) | | **Operating Temperature** | -40°C to +125°C | --- ### 2. Part Number Breakdown The nomenclature follows UTC’s internal coding system: * **LR1801**: Series name (1A LDO Regulator). * **L**: Lead-free/Halogen-free plating. * **15**: Output voltage identification (1.5 Volts). * **SH2**: Package code (SOT-263-5L). * **R**: Packing style (Tape and Reel). --- ### 3. Pin Configuration (Typical SOT-263) | Pin Number | Function | Description | | :--- | :--- | :--- | | 1 | **EN / NC** | Enable pin (high to turn on) or No Connection. | | 2 | **VIN** | Unregulated Input Voltage. | | 3 | **GND** | Ground Reference. | | 4 | **VOUT** | Regulated 1.5V Output. | | 5 | **FB / NC** | Feedback (for adjustable versions) or No Connection. | --- ### 4. Key Features & Applications #### Features: * **Low Dropout:** Allows the device to regulate even when the input voltage is only slightly higher than the output voltage. * **Protection Circuits:** Includes built-in thermal shutdown and current limiting to prevent damage during fault conditions. * **Stability:** Optimized for use with low-ESR ceramic capacitors. #### Applications: * **Battery-Powered Equipment:** Due to low quiescent current. * **Post-Regulators:** Used after switching power supplies to reduce noise for sensitive analog circuits. * **Microcontrollers:** Providing 1.5V core voltage for specific DSPs or FPGAs. * **Portable Electronics:** Smartphones, tablets, and handheld devices. --- ### 5. Typical Application Circuit ```text Vin ----[ In LR1801L Out ]---- Vout (1.5V) [ GND ] | Cin (10uF) ground Cout (10uF) ```