The **VIPER114HSTR** is a high-voltage converter belonging to the VIPerPlus family by STMicroelectronics. It is specifically designed for smart power supplies and Internet of Things (IoT) applications, integrating an 800 V avalanche-rugged power MOSFET with a PWM controller. --- ### ## Technical Specifications Overview The following table summarizes the key electrical characteristics of the VIPER114HSTR: | Parameter | Description | Typical Value | | :--- | :--- | :--- | | **Drain-Source Voltage** | Maximum voltage across the MOSFET | 800 V | | **Switching Frequency** | Fixed internal frequency | 60 kHz | | **RDS(on)** | MOSFET On-resistance | 14 $\Omega$ | | **$I_{DLIM}$** | Drain current limit | 400 mA | | **Supply Voltage ($V_{CC}$)** | Operating range | 4.5 V to 30 V | | **Package** | Surface mount package | SSOP10 | --- ### ## Core Electronic Components & Features The device integrates several critical electronic functions into a single silicon chip: #### 1. Power Stage * **800 V Power MOSFET:** The high breakdown voltage allows the chip to handle significant spikes and work safely with universal input voltages (85 VAC to 265 VAC) without external protection components. #### 2. Control & Modulation * **PWM Controller:** Uses current-mode control to regulate the output voltage. * **Jittering:** The switching frequency is slightly modulated (frequency jittering) to reduce Electromagnetic Interference (EMI), lowering the cost of input filters. #### 3. Protection Circuitry The chip includes comprehensive embedded protection features to ensure reliability: * **Pulse-at-Pulse Overcurrent Protection (OCP):** Limits the peak current in the MOSFET. * **Thermal Shutdown:** Shuts down the device if the junction temperature exceeds $150^\circ C$. * **Overvoltage Protection (OVP):** Protects against feedback loop failures. * **Short Circuit Protection:** Protects the system during a secondary-side short. --- ### ## Typical Application Circuit In a standard Flyback converter, the VIPER114HSTR replaces the discrete MOSFET and the PWM IC. ```mermaid graph LR Input[AC Input] --> Rect[Rectifier & Filter] Rect --> Transformer[High Frequency Transformer] Transformer --> VIPER[VIPER114HSTR] VIPER --> Feedback[Optocoupler/Feedback Loop] Feedback --> VIPER Transformer --> Output[DC Output] ``` --- ### ## Key Advantages * **Low Standby Power:** Consumes less than 10 mW at 230 VAC in no-load conditions, meeting strict energy-saving regulations. * **Reduced BOM:** Eliminates the need for an external startup circuit because it features an integrated high-voltage startup current source.