The **VIPer012LS** is a low-power, high-performance offline power converter manufactured by STMicroelectronics. It belongs to the **VIPerPlus** family, integrating a dedicated current-mode PWM controller with a high-voltage Power MOSFET on the same silicon chip. --- ## 1. Key Component Specifications The VIPer012LS is designed specifically for SMPS (Switched-Mode Power Supplies) with very low standby power consumption. | Feature | Specification | | :--- | :--- | | **Drain-Source Voltage ($V_{DSS}$)** | 800 V | | **Switching Frequency** | 60 kHz (fixed) | | **Package** | SSOP10 (Small Outline) | | **Max Output Power** | ~5W (Wide Range) / ~8W (European Range) | | **Standby Power** | < 10 mW at 230 $V_{AC}$ | | **Integration** | PWM Controller + 800V MOSFET + Startup Circuit | --- ## 2. Internal Electronic Architecture The internal circuitry of the VIPer012LS is composed of several critical functional blocks: ### A. The Power MOSFET The device features an **800V rugged MOSFET**. The high breakdown voltage allows for a simplified design by reducing the need for complex clamping circuits to handle voltage spikes during the "OFF" cycle. ### B. High Voltage Startup Unlike traditional controllers that require an external resistor to start up, the VIPer012LS includes an internal **high-voltage current source**. Once the chip reaches its $V_{CC(ON)}$ threshold, the internal source turns off to save power. ### C. The PWM Controller It utilizes **Current Mode Control**, which provides: * Better line regulation. * Inherent pulse-by-pulse current limiting. * Simplified frequency compensation. --- ## 3. Pin Configuration (SSOP10) | Pin Name | Function | Description | | :--- | :--- | :--- | | **GND** | Ground | Reference ground for the control logic. | | **VCC** | Supply Voltage | Power supply for the internal control logic. | | **FB** | Feedback | Input for the feedback loop (usually via optocoupler). | | **LIM** | Current Limit | Allows setting an external current limit (optional). | | **DRAIN** | Power MOSFET Drain | Connection to the primary winding of the transformer. | --- ## 4. Protection Features The electronic design includes several embedded safety mechanisms to protect the power supply from failure: 1. **Pulse-by-Pulse Overcurrent Protection (OCP):** Limits the peak current through the MOSFET in every cycle. 2. **Hysteretic Thermal Shutdown:** The chip shuts down if the junction temperature exceeds 150°C. 3. **Overvoltage Protection (OVP):** Protects the $V_{CC}$ pin from voltage spikes. 4. **Short-Circuit Protection:** Detects if the output is shorted and enters "burst mode" to prevent overheating. --- ## 5. Typical Application Circuit In a standard application, the VIPer012LS acts as the primary switcher in a **Flyback Converter**. ```mermaid graph LR AC_Input --> Rectifier Rectifier --> Transformer_Primary Transformer_Primary --> VIPer012LS_Drain VIPer012LS_Source --> GND Optocoupler --> VIPer012LS_FB ```