As manufacturers continue to develop more energy-efficient power supplies while meeting increasingly stringent eco-design regulations, reducing component count without compromising performance has become a key design priority. Addressing these requirements, STMicroelectronics has introduced the L6462A, a transition-mode (TM) power factor correction (PFC) controller designed for consumer products and power supplies up to 250W. The device combines a simplified architecture with high-efficiency operation, enabling designers to lower bill-of-materials (BOM) costs while improving overall power conversion performance.
At the core of the L6462A is a multiplier-less control architecture that replaces the conventional voltage sensor and analog multiplier with an integrated current generator and shaper to produce a sinusoidal reference signal. This eliminates the need for external voltage-divider components in boost-PFC converters, reducing circuit complexity and component count. In addition, the controller detects inductor demagnetization directly through the gate-driver output, removing the requirement for an auxiliary inductor winding and associated interface circuitry, further simplifying system design.
The innovative control scheme also enhances electrical performance by minimizing total harmonic distortion (THD) and improving efficiency, particularly under intermediate and light-load operating conditions. At full load, the controller operates in quasi-resonant valley-switching mode to reduce switching losses, while valley skipping progressively lowers the switching frequency as the load decreases to maintain high efficiency. A deep burst-mode threshold also enables smooth dimming performance in LED lighting applications, making the controller suitable for battery chargers, power adapters, flat-panel televisions, LED drivers, and other consumer power supplies.
Technically, the L6462A supports a universal AC input voltage range of 90–264V and is typically configured to deliver a 400V output. The device incorporates an enhanced error amplifier and a high-accuracy voltage reference to improve transient response and minimize output overshoot and undershoot during load changes. Its integrated totem-pole gate driver delivers up to +600mA/-300mA drive current for external boost MOSFETs and features active pull-down protection during under-voltage lockout. Additional integrated protections include overcurrent protection, output overvoltage protection, feedback failure detection, inductor saturation and short-circuit protection, along with a remote enable/disable function for system control.
To accelerate product development, STMicroelectronics also offers the EVL6462A-250W-M demonstration board, a compact 250W PFC pre-regulator supporting universal AC input. The evaluation platform achieves over 97% peak efficiency, with THD below 5% at full load and below 15% down to 20% load, demonstrating the controller's high-performance operation. Designers can further optimize implementations using ST's eDesignSuite Power Supply Design tool, eDSim simulation platform, and the accompanying AN6380 application note, which details the board's operating modes and measured performance. The L6462A is currently available in a compact SOT23-6L package.
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About STMicroelectronics
STMicroelectronics is a global semiconductor company that designs and manufactures analog, power management, microcontroller, sensing, and embedded processing technologies for automotive, industrial, consumer electronics, communications, and energy applications. Its portfolio includes advanced power conversion solutions, wide-bandgap semiconductor technologies, and energy-efficient control ICs that help designers improve performance, reduce system complexity, and meet evolving energy efficiency standards across a wide range of electronic systems.
