The XDPL8221 from Infineon is a digital dual-stage Power Factor Correction (PFC) and flyback power controller IC for AC-DC LED drivers which provides constant-current and constant-voltage outputs and supports PWM dimming functionality.
It features a UART serial interface which enables any microcontroller, sensor or wireless control device to directly configure the driver’s maximum current and the dimming level with simple UART commands. The UART interface also enables an external device to retrieve status information and monitor driver operational data in real time.
Providing primary-side regulation, a digital control loop, system protection and other built-in functions, the controller reduces the number of external components required in an LED driver. The device, which has the orderable part number XDPL8221XUMA1, also enables the use of small bus and output capacitors.
Unlike fixed-function analog power controllers, the digital XDPL8221 provides one-time programmable configuration options which enable OEMs to adjust features of the chip’s operation, such as the output current limit or the maximum output power, for use in different applications. The XDPL8221 therefore enables customizable LED driver designs, and simplifies the generation and maintenance of multiple board variants while keeping the number of stock-keeping units to a minimum.
The dual-stage XDPL8221 separates the quasi-resonant PFC function from the output-current regulation circuit. This ensures that there is low variation in the output current, reducing the flicker effect on the LED light output to a level that cannot be perceived. The flyback controller stage automatically switches between quasi-resonant, discontinuous conduction and active burst modes to provide the best performance for the application conditions.
This results in outstanding electrical performance including a power factor of >0.9 and total harmonic distortion of <15%. The dim-to-off feature with low stand-by power of <100mW reduces the non-active power consumption of the device.
Infineon’s REF-XDPL8221-U50W reference design