The **VIPERGAN65** is a high-voltage power converter belonging to the VIPerPlus family by STMicroelectronics. It is an advanced "all-in-one" System-in-Package (SiP) designed for high-efficiency Switch Mode Power Supplies (SMPS). The standout feature of this component is the integration of a **Gallium Nitride (GaN)** power transistor, which allows for higher switching frequencies and smaller form factors compared to traditional silicon-based chips. --- ### 1. Key Internal Components The VIPERGAN65 combines several electronic stages into a single QFN 5x6 mm package: | Component | Description | | :--- | :--- | | **650V GaN HEMT** | The power switch. GaN provides lower $R_{DS(on)}$ and faster switching than Silicon. | | **PWM Controller** | An advanced controller that manages the switching logic and duty cycle. | | **HV Startup** | Internal high-voltage startup circuitry that eliminates the need for external resistors. | | **SenseFET** | Integrated current sensing for cycle-by-cycle current protection. | --- ### 2. Technical Specifications Below are the primary electrical characteristics for the VIPERGAN65: * **Drain-Source Voltage ($V_{DSS}$):** 650 V * **Maximum Output Power:** Up to 65W (in Quasi-Resonant mode). * **Operating Modes:** * **Quasi-Resonant (QR):** To minimize switching losses. * **Frequency Foldback:** To maintain efficiency during medium/light loads. * **Burst Mode:** For ultra-low power consumption during no-load conditions (< 30 mW). * **Switching Frequency:** Up to 240 kHz. --- ### 3. Protection Features The chip includes a robust suite of integrated safety mechanisms to protect the power supply circuit: 1. **Overvoltage Protection (OVP):** Protects the load if the output voltage rises too high. 2. **Overload Protection (OLP):** Prevents damage during short circuits or excessive power draw. 3. **Brown-out Protection:** Monitors the input AC line voltage to ensure the system only operates within safe voltage ranges. 4. **Thermal Shutdown (OTP):** Automatically shuts down the device if the junction temperature exceeds $150^\circ C$. --- ### 4. Typical Application Circuit A typical circuit using the VIPERGAN65 follows a **Flyback Topology**. Because the GaN transistor is integrated, the external Bill of Materials (BOM) is significantly reduced. ```mermaid graph LR AC_Input --> Rectifier Rectifier --> Transformer_Primary Transformer_Primary --> VIPERGAN65 VIPERGAN65 --> Ground Transformer_Secondary --> Output_Rectifier Output_Rectifier --> DC_Output DC_Output -.-> Optocoupler_Feedback Optocoupler_Feedback -.-> VIPERGAN65 ``` --- ### 5. Advantages of using GaN in VIPERGAN65 * **Efficiency:** Higher power conversion efficiency (often >90%). * **Size:** Smaller transformers and capacitors can be used due to higher switching frequencies. * **Thermal Management:** Less heat is generated compared to MOSFET-based converters.