The **R25LD10-TF4-R** is a specific low-dropout (LDO) linear voltage regulator manufactured by **UTC (Unisonic Technologies)**. It is designed to provide a stable, regulated output voltage with minimal difference between the input and output voltages. --- ## 1. Technical Specifications Below are the primary technical parameters for the R25LD10-TF4-R: | Parameter | Specification | | :--- | :--- | | **Output Voltage ($V_{OUT}$)** | 2.5V (Fixed) | | **Max Output Current ($I_{OUT}$)** | 1.0A | | **Dropout Voltage ($V_{DROP}$)** | Typically 0.5V @ 1A | | **Operating Input Voltage ($V_{IN}$)** | Up to 12V | | **Package Type** | TO-252 (DPAK) | | **Operating Temperature** | -40°C to +125°C | --- ## 2. Pin Configuration The device usually follows a standard 3-pin configuration for the TO-252 package: 1. **Pin 1 (Input - $V_{IN}$):** The unregulated DC supply input. 2. **Pin 2 (Ground/Case):** Common ground connection, also acts as a heat sink. 3. **Pin 3 (Output - $V_{OUT}$):** Regulated 2.5V output. --- ## 3. Key Features * **Low Dropout Voltage:** Efficiently operates even when the input voltage is only slightly higher than the 2.5V output. * **Internal Protection:** * **Current Limiting:** Protects the device during overload or short-circuit conditions. * **Thermal Shutdown:** Shuts down the regulator if the junction temperature exceeds safe limits to prevent permanent damage. * **Stability:** Designed to be stable with low-ESR ceramic or tantalum output capacitors. --- ## 4. Part Number Breakdown The naming convention for UTC parts follows a specific logic: * **R25:** Indicates a fixed output voltage of **2.5V**. * **LD10:** Refers to the series (**L**ow **D**ropout) and the current rating (**1.0A**). * **TF4:** Specifies the **TO-252** package type. * **R:** Indicates **Tape & Reel** packaging for automated assembly. --- ## 5. Typical Application Circuit To ensure stability, external capacitors are required: ```c Input (Vin) ----[ C1 ]---- (Pin 1) [ R25LD10 ] (Pin 3) ----[ C2 ]---- Output (2.5V) | | (Pin 2) GND | GND ``` * **C1 (Input Capacitor):** 10µF Tantalum or Electrolytic to filter supply noise. * **C2 (Output Capacitor):** 10µF to 22µF to ensure loop stability and transient response.