Infineon PSB21393HV3: High-Voltage Offline SMPS Start-Up Controller
In the realm of power electronics, designing efficient and reliable offline Switch-Mode Power Supplies (SMPS) presents a significant challenge, particularly in the start-up phase. The Infineon PSB21393HV3 emerges as a specialized high-voltage start-up controller engineered to address these challenges, offering a robust and intelligent solution for a wide range of AC-DC power conversion applications.
The primary role of this IC is to manage the initial power-up sequence of the main SMPS controller and its associated circuitry. Traditional start-up methods often rely on a simple resistor dropper, which incurs substantial standby power losses. The PSB21393HV3 dramatically improves system efficiency by eliminating this constant power drain. It features a high-voltage startup cell that can be connected directly to the rectified high-voltage DC bus, allowing it to operate with input voltages of up to 615V. This capability makes it exceptionally suitable for universal mains applications (85 VAC to 265 VAC).
Its operation is elegantly straightforward yet highly effective. Upon application of AC power, a small current is sourced through the internal high-voltage JFET to charge an external storage capacitor connected to the VCC pin. Once the voltage on this capacitor reaches a predefined start-up threshold, the IC activates its internal regulator, providing a stable supply voltage to the downstream PWM controller. After the main SMPS controller is active and its auxiliary winding begins to generate power, the PSB21393HV3 automatically switches off its internal high-voltage current source. This handover process is crucial, as it drastically reduces the IC's own operating current to a very low quiescent level, minimizing the total standby power consumption of the power supply to well below 100mW, and often even lower.
Furthermore, the device incorporates comprehensive protection features to enhance system reliability. It includes built-in over-temperature protection (OTP) and over-voltage protection (OVP) on the VCC pin, safeguarding both itself and the connected PWM controller from fault conditions. Its robust design ensures stable operation across a wide industrial temperature range.
The Infineon PSB21393HV3 is, therefore, an ideal choice for designers seeking to create power supplies that must meet stringent energy efficiency regulations like ErP, Energy Star, or CoC. Its applications span across consumer electronics, industrial systems, appliances, and auxiliary power supplies for inverters, where high reliability and low standby power are paramount.
The Infineon PSB21393HV3 is a pivotal component for modern, eco-conscious power supply design. It masterfully solves the high-voltage start-up challenge by providing a highly integrated, efficient, and protected method to initialize offline SMPS. Its key contribution lies in its ability to enable ultra-low standby power consumption without compromising robustness or reliability, making it an excellent enabler for next-generation energy-efficient power systems.
Keywords:
1. Standby Power Consumption
2. High-Voltage Startup
3. Offline SMPS
4. Start-Up Controller
5. Energy Efficiency
