The **VIPER06LS** is an offline high-voltage converter from STMicroelectronics, belonging to the VIPerPlus family. It is specifically designed for low-power Switch Mode Power Supplies (SMPS). It integrates an 800V avalanche-rugged MOSFET with a PWM controller in a single package. --- ### 1. Key Internal Components The VIPER06LS contains several critical electronic sub-systems integrated into the silicon: | Component | Function | | :--- | :--- | | **Power MOSFET** | An 800V $BV_{dss}$ rated transistor that handles high voltage switching. | | **PWM Controller** | Manages the switching frequency and duty cycle based on feedback. | | **SenseFET** | A special transistor structure used for lossless current sensing. | | **High Voltage Startup** | Allows the chip to power itself directly from the rectified mains. | | **Oscillator** | Fixed switching frequency (60 kHz) with jittering to reduce EMI. | --- ### 2. Technical Specifications The "LS" variant typically refers to specific frequency and packaging characteristics (often the SSOP10 package). | Parameter | Value / Description | | :--- | :--- | | **Drain-Source Voltage ($V_{DS}$)** | 800 V (Minimum) | | **Switching Frequency** | 60 kHz (Fixed) | | **Max Power Output** | ~7W (Wide range) / ~10W (European range) | | **Standby Power** | < 30 mW at 265 $V_{AC}$ | | **Protection Features** | Thermal shutdown, Overload, Short-circuit | --- ### 3. Pinout Description (SSOP10) Below are the primary pin functions for the VIPER06LS: 1. **GND**: Ground for the controller and source of the power MOSFET. 2. **VCC**: Supply voltage for the internal control logic (usually fed via an auxiliary winding). 3. **FB**: Feedback input for regulation (connects to an optocoupler or resistive divider). 4. **LIM**: Current limit set point (allows adjustment of the maximum peak primary current). 5. **DRAIN**: High voltage connection to the transformer primary winding. --- ### 4. Features and Application Advantages * **Frequency Jittering:** The switching frequency varies slightly over time. This spreads the energy of the electromagnetic interference (EMI), making it easier to pass regulatory certifications with smaller filters. * **Burst Mode Operation:** Under light loads, the device enters a "burst" mode to reduce switching losses, ensuring high efficiency even when the device is idling. * **Protection Suite:** * **Auto-restart:** If a fault (like a short circuit) occurs, the device stops and periodically tries to restart. * **Hysteretic Thermal Shutdown:** Shuts down if the internal silicon temperature exceeds 150°C. --- ### 5. Common Applications * Power supplies for home appliances (washing machines, refrigerators). * LED lighting drivers. * Wall adapters and chargers. * Auxiliary power for industrial systems.