The **LR1801G-33-SH2-R** is a low-dropout (LDO) linear regulator manufactured by Unisonic Technologies (UTC). It is designed to provide a stable, fixed output voltage from a higher input voltage with very low noise and high power supply rejection. --- ### 1. Key Technical Specifications | Parameter | Specification | |:---|:---| | **Part Number** | LR1801G-33-SH2-R | | **Output Voltage** | 3.3V (Fixed) | | **Output Current** | 300mA - 600mA (Depending on thermal conditions) | | **Input Voltage Range** | Up to 6V | | **Package Type** | SOT-263 (SH2) | | **Accuracy** | ±2.0% | | **Drop-out Voltage** | Very Low (Typ. 150mV @ 100mA) | | **Mounting Type** | Surface Mount (SMD) | --- ### 2. Functional Characteristics * **Fixed Output:** The "33" in the part number indicates a fixed **3.3V** output. It does not require external resistors to set the voltage. * **Low Dropout (LDO):** It can maintain a 3.3V output even when the input voltage is very close to 3.3V, maximizing battery life and efficiency. * **Protection Circuits:** * **Current Limit:** Prevents damage during an output short-circuit. * **Thermal Shutdown:** Automatically turns off the device if the internal temperature exceeds safe limits. * **Green/Halogen Free:** The "G" suffix indicates that the part is compliant with environmental "Green" standards (Halogen-Free and RoHS compliant). --- ### 3. Pin Configuration (Typical SOT-263) While pinouts can vary by specific manufacturer revisions, the standard functional blocks for this LDO are: 1. **VIN:** Input voltage supply. 2. **GND:** Ground reference. 3. **VOUT:** Regulated 3.3V output. 4. **EN (Enable):** Logic high to turn on the device, logic low to enter shutdown mode (reducing current draw). --- ### 4. Application Areas The LR1801G-33 is commonly used in battery-powered or portable electronics where space and power efficiency are critical: * **Microcontrollers (MCU):** Powering 3.3V logic circuits. * **Wireless Modules:** Bluetooth or Wi-Fi modules requiring clean, stable power. * **Consumer Electronics:** Handheld GPS, digital cameras, and tablets. ---