STMicroelectronics launches multiplier-less PFC controller for efficient 250W designs

STMicroelectronics has introduced the L6462A transition-mode power-factor correction controller for cost-sensitive power supplies up to 250W. The chip targets battery chargers, adapters, TVs and lighting drivers, with low standby power, high efficiency and simplified external circuitry. Why it matters: - The L6462A is aimed at consumer and industrial power designs that need lower bill-of-materials costs without giving up efficiency. - The controller is designed to help power supplies up to 250W meet stricter eco-design requirements. - The part targets battery chargers, power adapters, flat-panel TV power supplies and LED lighting drivers. What happened: - STMicroelectronics introduced the L6462A transition-mode power-factor correction controller for boost-PFC applications. - The device is in production now. - The controller comes in a SOT23-6L package. - Pricing starts at $0.18 in 1,000-piece orders. The details: - The L6462A uses a current generator and shaper to create a sinusoidal reference instead of a conventional voltage sensor and analog multiplier. - The design removes the need for external voltage-divider components in boost-PFC converters. - The IC senses inductor demagnetization through the gate-driver output, eliminating the need for an auxiliary inductor winding or interface components. - The controller’s current shaping and demagnetization sensing reduce total harmonic distortion and improve efficiency, especially at intermediate and light loads. - Idle current is below 60µA, which supports low-standby-power requirements. - At full load, the controller runs in quasi-resonant valley-switching mode to reduce power dissipation. - At lighter loads, valley skipping lowers operating frequency to preserve efficiency. - A deep burst-mode threshold supports smooth dimming in LED-lighting applications. - The L6462A supports a 90V to 264V AC input range and is typically used to generate a 400V output. - An enhanced error amplifier and high-accuracy voltage reference improve transient response and limit overshoot and undershoot. - The totem-pole output drives external boost-converter MOSFETs directly with up to +600mA/-300mA drive capability. - The IC includes active pulldown for safety during undervoltage lockout. - The controller also includes a disable function for remote on/off control. - Built-in protection covers overcurrent, output overvoltage, feedback failure and inductor saturation or short-circuit conditions. - STMicroelectronics also offers the EVL6462A-250W-M demonstration board to help evaluate the controller’s features. - The board is a 250W PFC pre-regulator with a universal input-voltage range. - The demo board achieves over 97% peak efficiency. - The board records THD below 5% at full load and below 15% down to 20% load. - Application note AN6380 covers the board’s operating modes and performance measurements. - STMicroelectronics’ Power Supply Design tool in eDesignSuite can help customize the circuit. - eDsim supports device simulations. - More information is available in STMicroelectronics’ announcement . Between the lines: - The chip’s multiplier-less architecture and removal of external sensing parts point to a push for simpler, smaller and cheaper power stages. - The mix of low standby current, high peak efficiency and light-load performance suggests STMicroelectronics is targeting energy rules that are increasingly important in consumer electronics. - The demo board and software tools indicate STMicroelectronics is trying to shorten design time as well as cut component count. What’s next: - Designers can evaluate the L6462A now using the EVL6462A-250W-M board and related design tools. - The broader adoption question is whether cost-sensitive power designs will favor the simplified architecture as much as the company expects. The bottom line: - STMicroelectronics is betting that fewer external parts, lower standby power and strong efficiency will make the L6462A attractive for compact, regulation-sensitive power supplies.