The **STLQ50C-R** is a high-performance, low-dropout (LDO) linear voltage regulator designed by STMicroelectronics. It is specifically engineered for low-power applications where battery longevity and minimal space are critical. --- ## 1. Technical Specifications The STLQ50C-R belongs to the STLQ50 series. Below are its primary technical characteristics: | Feature | Specification | | :--- | :--- | | **Input Voltage Range** | 2.3 V to 12 V | | **Output Voltage (Fixed)** | 5.0 V | | **Output Current** | Up to 50 mA | | **Quiescent Current ($I_q$)** | Typ. 3 µA (at no load) | | **Dropout Voltage** | 200 mV (at 50 mA load) | | **Package Type** | SOT-323-5L (SC-70) | | **Operating Temperature** | -40°C to 125°C | --- ## 2. Key Internal Components & Features ### A. Low Quiescent Current Control The internal circuitry is optimized to consume only **3 µA** of current. This makes the part ideal for "Always-On" devices that spend most of their time in standby mode. ### B. Control Logic (Enable Pin) The STLQ50C-R features a logic-controlled **Shutdown Mode**. * When the Enable (EN) pin is pulled low, the device enters a standby state. * In this state, current consumption drops to virtually zero ($< 1$ µA). ### C. Protection Circuitry The chip integrates several safety mechanisms to prevent hardware failure: 1. **Current Limit:** Protects the regulator if the output is shorted to ground. 2. **Thermal Shutdown:** Automatically turns off the device if the internal junction temperature exceeds safe limits. --- ## 3. Application Circuitry To ensure stability, the STLQ50C-R requires minimal external components. Typically, it only requires two small ceramic capacitors. ```markdown Vin ----[ C1 (1uF) ]---- (Vin Pin) [ STLQ50C-R ] (Vout Pin) ----[ C2 (1uF) ]---- Vout (5V) | | (GND) (EN) ``` ### Components List: * **Input Capacitor (C1):** 1 µF ceramic capacitor is recommended to filter input noise. * **Output Capacitor (C2):** 1 µF (min) ceramic capacitor is required for stability. High ESR capacitors should be avoided. --- ## 4. Typical Use Cases * **IoT Sensors:** Devices that wake up periodically to send data. * **Battery-Powered Portables:** Wearables or handheld meters using Li-ion or Alkaline batteries. * **Automotive Subsystems:** Low-power modules that remain active when the engine is off.