The **US202ALG-AF5-R** is a high-precision, low-dropout (LDO) linear voltage regulator manufactured by UTC (Unisonic Technologies Co., Ltd). It is specifically designed for applications requiring high stability and low noise in compact electronic circuits. --- ### 1. General Specifications The following table summarizes the key technical parameters of the US202ALG-AF5-R: | Parameter | Specification | | :--- | :--- | | **Component Type** | LDO Linear Voltage Regulator | | **Output Type** | Adjustable (ADJ) | | **Max Output Current** | 200 mA | | **Input Voltage Range** | 2.5V to 6.0V | | **Dropout Voltage** | ~150mV @ 100mA | | **Package Type** | SOT-25 / SOT-23-5 | | **Operating Temperature** | -40°C to +85°C | --- ### 2. Pin Configuration The device typically comes in a 5-pin SOT-25 package. The pinout is crucial for PCB layout: | Pin Number | Name | Function | | :---: | :--- | :--- | | 1 | **VIN** | Input Voltage Supply | | 2 | **GND** | Ground | | 3 | **EN** | Enable (High = On, Low = Shutdown) | | 4 | **ADJ** | Feedback/Adjust Pin for setting voltage | | 5 | **VOUT** | Regulated Output Voltage | --- ### 3. Key Electronic Features * **Adjustable Output:** Unlike fixed-voltage regulators, the "ADJ" version allows the designer to set the output voltage using an external resistor divider connected to the ADJ pin. * **Low Quiescent Current:** It draws very little power during operation, making it ideal for battery-powered handheld devices. * **Stability with Ceramic Capacitors:** The internal compensation is designed to be stable even when using low-ESR ceramic capacitors at the output. * **Protection Circuitry:** * **Thermal Shutdown:** Protects the IC if it overheats. * **Current Limiting:** Prevents damage during short-circuit conditions. --- ### 4. Typical Application Circuit To use this part, a basic circuit setup is required: ```mermaid graph LR Vin[Input Voltage] --> C1[Input Cap 1uF] C1 --> IC[US202ALG] IC --> C2[Output Cap 1uF] IC --> R1[Resistor 1] R1 --> R2[Resistor 2] R2 --> GND[Ground] IC -.-> ADJ[Feedback Loop] ``` --- ### 5. Part Number Decoding (UTC Standard) * **US202**: Series Name (200mA LDO). * **A**: Adjustable version. * **L**: Lead-free/Halogen-free. * **G**: Green Package. * **AF5**: Package Code (SOT-25). * **R**: Tape and Reel packaging.