The **LP2950L-33-T92-R** is a popular low-dropout (LDO) linear voltage regulator. It is designed to provide a stable, fixed output voltage while maintaining a very low quiescent current, making it ideal for battery-powered applications. --- ### 1. Part Number Breakdown Understanding the suffix codes helps in identifying the specific variant of this component: | Code Segment | Meaning | | :--- | :--- | | **LP2950** | Series Name (Low Dropout Regulator) | | **L** | Lead-free / RoHS Compliant | | **33** | Output Voltage (3.3V) | | **T92** | Package Type (TO-92) | | **R** | Packing Style (Tape & Reel) | --- ### 2. Key Technical Specifications The device is characterized by its efficiency in stepping down voltage with minimal energy loss. | Parameter | Value | | :--- | :--- | | **Output Voltage** | 3.3V (Fixed) | | **Max Input Voltage** | 30V | | **Output Current** | 100mA (Maximum) | | **Dropout Voltage** | ~40mV (at light loads), ~380mV (at 100mA) | | **Quiescent Current** | 75µA (Typical) | | **Operating Temp** | -40°C to +125°C | --- ### 3. Pinout Configuration The **TO-92** package is a small, plastic three-pin package resembling a transistor. | Pin Number | Name | Description | | :--- | :--- | :--- | | **1** | **Vout** | Regulated 3.3V Output | | **2** | **GND** | Ground | | **3** | **Vin** | Unregulated Input Voltage | --- ### 4. Features and Applications #### Features - **Extremely Low Quiescent Current:** Reduces power drain when the device is in standby. - **Low Dropout Voltage:** Can maintain a 3.3V output even when the input voltage is only slightly above 3.3V (e.g., 3.7V). - **Tight Regulation:** High accuracy in maintaining the output voltage despite changes in load or input. - **Protection:** Includes internal current limiting and thermal shutdown. #### Common Applications 1. **Battery Powered Systems:** Prolongs battery life in handheld meters or remote sensors. 2. **Microcontroller Power:** Providing stable 3.3V to MCUs like ESP8266, STM32, or low-power Arduinos. 3. **Linear Post-Regulators:** Used after a switching regulator to filter out high-frequency noise. --- ### 5. Standard Implementation Circuit To ensure stability, LDOs require external capacitors. ```mermaid graph LR Input -->|Vin| LP2950 LP2950 -->|Vout| Output LP2950 --- Ground ``` * **Input Capacitor:** A 1µF tantalum or electrolytic capacitor is recommended to filter input noise. * **Output Capacitor:** A minimum of **1µF to 2.2µF** is essential for stability. The ESR (Equivalent Series Resistance) of this capacitor is critical for preventing oscillation.