The PT1929 is an ultra-high-voltage linear constant-power LED driver IC with a maximum input voltage of up to 400V, designed for driving high-voltage, low-current LED loads. The application circuit requires very few external components and features a compact layout, making it simple and flexible for use in various small-sized or flat-panel LED products. The PT1929 provides a constant current output ranging from 5mA to 150mA. It integrates a multiplier circuit that greatly improves the system power factor and achieves extremely low system THDi (meeting the highest IEC standards). In addition, its simple linear driving method eliminates the need for magnetic components, effectively avoiding EMI interference issues.

The PT1929 adopts a patented closed-loop control method to achieve constant-current output control, offering excellent line regulation and load regulation performance. It maintains a constant average output current within a certain input voltage range. At the same time, the PT1929 continuously monitors the mains voltage to realize constant input power functionality.

To prevent damage caused by overheating, the PT1929 integrates an intelligent thermal control function. When the internal junction temperature rises to 142°C, the PT1929 begins reducing the output current. When the junction temperature reaches 160°C, the output current is reduced to zero.