STMicroelectronics HVLED101 90-400V flyback controller

STMicroelectronics has launched the HVLED101 90-400V flyback controller for LED-lighting applications up to 180 W. The integrated flyback controller is designed to enhance performance and simplify design through feature integration, patented control techniques and support for primary-sending regulation.

The flyback controller contains 800 V startup circuitry that reduces the LED turn-on time to less than 250 ms. High-voltage input-sending circuitry and a maximum power control (MPC) engine are also integrated to provide power output as the line voltage fluctuates. This lets designers choose smaller and lower-cost external passive components to handle worst-case line conditions. Primary-sending regulation without isolated feedback further reduces the bill of materials.

STMicroelectronics’ input-shaping algorithm is designed to lower total harmonic distortion (THD) and increase the power factor. The flyback controller also implements ST’s valley-locking technique to reduce audible noise, improve regulation and reduce distortion. At steady state in quasi-resonant operation, valley locking fixes the number of valleys skipped until a significant change in output power or input voltage is detected. Current shaping and valley locking enhance the power factor and THD, at low and maximum loads.

Designers can also program the delay time after zero-crossing detection in pure quasi-resonant operation using an external resistor. With gate turn-on at the lowest point of the valley, the flyback controller reduces energy losses and electromagnetic emissions (EMI), while enabling converters to achieve efficiency and no-load power. The device features built-in protection, including overcurrent protection, input voltage protection and brownout protection. There is also a smart auto-reload timer (ART) that enables latch-free operation of all protection mechanisms.

Two demonstration boards containing the flyback controller are available to jump-start development for faster time to market. The EVLHV101PSR50W is a 90–265 VAC, 60 V/0.8 A isolated flyback converter with primary-sending regulation, while the EVLHV101SSR50W is a similar design with secondary-sending regulation.

The HVLED101 is in production now in the narrow form-factor SO-14N package.