The **VIPERGAN** (often referred to as **VIPer-GaN**) is a series of high-voltage power converters from STMicroelectronics. These devices are "System-in-Package" (SiP) solutions that integrate a Gallium Nitride (GaN) power transistor with a sophisticated PWM controller. --- ### 1. Key Internal Components The VIPer-GaN family combines several electronic elements into a single 6x8 mm QFN package: | Component | Description | | :--- | :--- | | **GaN Power Transistor** | A 650V or 730V Gallium Nitride HEMT that provides high electron mobility and low RDS(on). | | **PWM Controller** | An advanced pulse-width modulation engine that handles startup, regulation, and protection. | | **SenseFET Architecture** | Built-in current sensing that eliminates the need for bulky external shunt resistors. | | **Startup Regulator** | An internal high-voltage startup cell that allows the chip to power itself directly from the rectified mains. | --- ### 2. Technical Specifications The use of GaN technology allows these parts to operate at much higher frequencies and efficiencies than traditional Silicon (Si) MOSFETs. * **Drain-Source Voltage ($V_{DS}$):** Typically 650V to 730V (robust against line surges). * **Operating Modes:** * **Quasi-Resonant (QR):** Minimizes switching losses. * **Frequency Folding:** Improves efficiency during medium/light loads. * **Burst Mode:** Reduces power consumption to < 30mW during no-load conditions. * **Switching Frequency:** Up to 240 kHz (allows for smaller transformers/inductors). --- ### 3. Protection Features One of the main advantages of the VIPer-GaN series is the integrated suite of protection circuits: 1. **Overvoltage Protection (OVP):** Protects against feedback loop failures. 2. **Overload Protection (OLP):** Prevents damage during output short-circuits. 3. **Brown-out Protection:** Monitors input voltage to prevent operation during "sag" conditions. 4. **Thermal Shutdown:** Automatically turns off the device if the junction temperature exceeds safety limits (typically 150°C). --- ### 4. Applications Because of the high integration and efficiency of GaN, these parts are used in high-density power supplies: * **USB-C PD Chargers:** Fast chargers for smartphones and laptops. * **Home Appliances:** High-efficiency power boards for smart home devices. * **Industrial Power:** Auxiliary power supplies for servers and motor drives.