The **LR6401ML-AG6-R** is a high-performance, low-dropout (LDO) linear regulator manufactured by UTC (Unisonic Technologies Co.). It is designed specifically for applications requiring high stability, low noise, and low power consumption. --- ## 1. Technical Specifications The following table summarizes the primary electrical characteristics of the LR6401ML: | Parameter | Specification | | :--- | :--- | | **Input Voltage Range** | 2.5V to 6.0V | | **Output Voltage** | Fixed or Adjustable (Model dependent; often 1.2V–3.3V) | | **Maximum Output Current** | 300mA | | **Dropout Voltage** | ~200mV @ 100mA | | **Quiescent Current** | ~50µA (Typical) | | **Package Type** | SOT-26 / SOT-23-6 | | **Operating Temperature** | -40°C to +85°C | --- ## 2. Key Features * **Low Dropout Voltage:** Efficiently regulates voltage even when the input is very close to the desired output. * **Built-in Protections:** * *Thermal Shutdown:* Prevents damage from overheating. * *Current Limiting:* Protects the IC during short circuits or overcurrent events. * **High PSRR:** Excellent Power Supply Rejection Ratio, making it suitable for noise-sensitive RF and audio circuits. * **Enable Pin (EN):** Allows the chip to be put into a low-power "shutdown mode" to conserve battery life. --- ## 3. Pin Configuration (Typical SOT-26) In a standard SOT-26/AG6 package, the pins are generally assigned as follows: | Pin Number | Name | Description | | :---: | :--- | :--- | | 1 | **VIN** | Power Supply Input | | 2 | **GND** | Ground | | 3 | **EN** | Enable Input (High = On, Low = Off) | | 4 | **NC/BP** | No Connection or Bypass Capacitor | | 5 | **VOUT** | Regulated Output Voltage | | 6 | **FB/NC** | Feedback (for ADJ versions) or No Connect | --- ## 4. Typical Application Circuit To ensure stability, LDOs require external capacitors. Below is a representation of a standard setup: ```mermaid graph LR Vin[Input Voltage] --> C1[1uF MLCC] C1 --> IC[LR6401ML] IC --> C2[1uF MLCC] C2 --> Vout[Regulated Output] IC -- Pin 3 --> EN[Logic Control] ``` --- ## 5. Usage Guidelines 1. **Capacitor Selection:** Use Low-ESR ceramic capacitors (MLCC) for both input and output to maintain loop stability. 2. **Thermal Dissipation:** Ensure the PCB layout has enough copper area near the Ground pins to act as a heat sink if drawing the full 300mA current. 3. **Voltage Differential:** Always ensure $V_{IN} > V_{OUT} + V_{DROPOUT}$ for the regulator to function correctly.