The **L5100L-AF5-R** is a specific low-dropout (LDO) linear voltage regulator, commonly manufactured by UTC (Unisonic Technologies Co.). It is designed for applications requiring high precision and low noise in a compact form factor. --- ### 1. Technical Specifications Below are the primary electrical characteristics of the L5100L-AF5-R: | Feature | Specification | | :--- | :--- | | **Output Type** | Fixed Output | | **Output Voltage** | 5.0V | | **Input Voltage (Max)** | Up to 18V (varies by specific series version) | | **Output Current** | 300mA | | **Dropout Voltage** | Low (typically < 300mV at full load) | | **Package Type** | SOT-25 / SOT-23-5 | | **Operating Temperature** | -40°C to +125°C | --- ### 2. Part Number Breakdown Understanding the suffix codes helps in identifying the exact variant: * **L5100**: The base series name (Low Dropout Regulator). * **L**: Lead-free/Halogen-free designation. * **AF5**: Refers to the **SOT-25** (also known as SOT-23-5) package. * **R**: Indicates the packing method (**Tape & Reel**). --- ### 3. Pin Configuration (SOT-25) The device typically utilizes a 5-pin layout to provide additional control over the power delivery. | Pin Number | Name | Function | | :--- | :--- | :--- | | 1 | **VIN** | Input Supply Voltage | | 2 | **GND** | Ground | | 3 | **CE / EN** | Chip Enable (Active High) | | 4 | **NC / BYP** | No connection or Bypass Capacitor (for noise reduction) | | 5 | **VOUT** | Regulated Output Voltage | --- ### 4. Key Features & Applications * **High Accuracy:** Usually provides ±2% output voltage accuracy. * **Low Quiescent Current:** Ideal for battery-powered devices to extend life. * **Protection Circuits:** Includes thermal shutdown and current limit protection. * **Applications:** * Battery-powered equipment (Smartphones, Tablets). * Post-regulation for switching supplies. * Reference voltage sources for Microcontrollers (MCUs). --- ### 5. Application Circuit Example A typical implementation requires minimal external components: ```text [VIN] ----+----[ L5100L ]----+---- [VOUT] | (U1) | [C1] [C2] | | [GND] [GND] ``` * **C1 (Input Capacitor):** 1µF Ceramic (stable against line transients). * **C2 (Output Capacitor):** 2.2µF - 10µF Ceramic (critical for loop stability).