The **VIPER013L** is a high-voltage power converter from STMicroelectronics, part of the VIPerPlus family. It is specifically designed for high-performance off-line power supplies, integrating an 800V avalanche-rugged power MOSFET with a Pulse Width Modulation (PWM) controller. --- ### 1. Key Internal Components The VIPER013L integrates several electronic stages into a single monolithic chip to reduce external part counts: | Component | Function | | :--- | :--- | | **800V Power MOSFET** | Handles high input voltages and provides a high safety margin against voltage spikes. | | **PWM Controller** | Manages the switching frequency and duty cycle for voltage regulation. | | **High Voltage Startup** | Allows the chip to start directly from the rectified mains, eliminating the need for an external startup resistor. | | **Error Amplifier** | Features an integrated 1.2V reference for precise output regulation. | | **Protection Circuitry** | Includes thermal shutdown, overvoltage protection, and short-circuit protection. | --- ### 2. Pin Configuration (SSOP10 Package) The device is typically housed in an SSOP10 package. Below are the primary pin functions: | Pin Name | Description | | :--- | :--- | | **DRAIN** | Connected to the internal MOSFET drain. High voltage pin. | | **SOURCE** | Ground reference for the control circuits and MOSFET source. | | **VCC** | Supply voltage for the internal control logic. | | **FB (Feedback)** | Input for the feedback loop to regulate the output voltage. | | **CONT** | Used to adjust the switching frequency or limit current. | --- ### 3. Technical Specifications * **Drain-Source Voltage ($V_{DS}$):** 800V (minimum). * **Switching Frequency:** Fixed at 60 kHz (L-version). * **Idlim (Current Limit):** Integrated limit to protect the transformer from saturation. * **Power Consumption:** Extremely low (less than 10mW at no-load/standby). * **Jittering:** Built-in frequency jittering to reduce EMI (Electromagnetic Interference) emissions. --- ### 4. Typical Application Circuit The VIPER013L is most commonly used in **Flyback** or **Buck** converter topologies. Because it has an integrated error amplifier, it can be used in: 1. **Primary Regulation:** Sensing the voltage directly from the auxiliary winding. 2. **Secondary Regulation:** Using an optocoupler for higher precision isolation. --- ### 5. Notable Features * **Pulse Burst Mode:** When the load is very light, the device enters "Burst Mode" to minimize power consumption, making it ideal for meeting "Green Energy" standards. * **Soft Start:** Gradually increases the current limit during power-up to reduce mechanical stress on components. * **Auto-Restart:** Automatically attempts to restart the power supply after a fault (like a short circuit) is removed.