The **VIPER113XSTR** belongs to the VIPerPlus family of high-voltage converters developed by STMicroelectronics. It is an integrated offline power converter specifically designed for high-efficiency SMPS (Switched-Mode Power Supplies). --- ## 1. Key Component Overview The VIPER113XSTR integrates a **PWM controller** and an **800 V avalanche-rugged Power MOSFET** into a single small-outline package (SSOP10). This integration reduces the component count and PCB size for power supplies. ### Technical Specifications | Parameter | Description | | :--- | :--- | | **Drain-Source Voltage ($V_{DSS}$)** | 800 V | | **Drain Current ($I_{D}$)** | 350 mA (Peak) | | **Switching Frequency** | 30 kHz (Fixed) | | **Supply Voltage ($V_{CC}$)** | 4.5 V to 30 V | | **Package** | SSOP10 (Tape and Reel) | | **Topology Support** | Buck, Buck-Boost, Flyback | --- ## 2. Integrated Electronic Features ### A. High Voltage Startup The chip includes an internal high-voltage current source. When power is applied, it charges the $V_{CC}$ capacitor directly from the rectified mains, eliminating the need for external startup resistors and reducing standby power consumption. ### B. Control Logic & PWM The device uses **Current Mode Control**. This provides excellent line and load regulation and simplifies the compensation network. The internal 30 kHz oscillator is "jittered" to reduce EMI (Electromagnetic Interference) emissions. ### C. Protections (Embedded) The VIPER113XSTR is highly robust due to its built-in protection circuits: 1. **Overvoltage Protection (OVP):** Shuts down the device if the output voltage exceeds a threshold. 2. **Short Circuit Protection:** Protects the system during a secondary-side short. 3. **Thermal Shutdown:** Includes a sensor that disables switching if the junction temperature exceeds ~150°C. 4. **Pulse-by-Pulse Current Limit:** Limits the peak current through the MOSFET to prevent saturation. --- ## 3. Typical Application Circuit (Flyback) Below is a conceptual representation of how the pins are utilized in a standard circuit: ```mermaid graph LR Input[AC Mains] --> Rect[Bridge Rectifier] Rect --> VDRAIN[VIPER113 - Drain Pin] VDRAIN --> Trans[Transformer/Inductor] Trans --> Output[DC Out] Output --> FB[Feedback Optocoupler] FB --> FB_Pin[VIPER113 - FB Pin] ``` --- ## 4. Advantages and Use Cases * **Low Standby Power:** Consumes less than 10 mW at 230 $V_{AC}$ in no-load conditions. * **Safety:** The 800 V rating provides a high safety margin against voltage spikes on the AC line. * **Applications:** * Home appliances (washing machines, refrigerators). * Home automation (IoT sensors, smart switches). * LED lighting drivers. * Industrial auxiliary power supplies.