The RT7331 is a dimmable constant current LED driver with active power factor correction. It supports high power factor across a wide range of line voltages, and it drives the converter in the Quasi-Resonant (QR) mode to achieve the higher efficiency. By using Primary Side Regulation (PSR), the RT7331 controls the output current accurately without a shunt regulator and an opto-coupler at the secondary side, reducing the external component count, the cost, and the volume of the driver board.
The RT7331 is compatible with the analog dimming. The output current can be modulated by the PWM duty ratio or the average level of DIM pin.
The RT7331 embeds comprehensive protection functions for robust designs, including LED open-circuit protection, LED short-circuit protection, output diode short-circuit protection, VDD Under-Voltage Lockout (UVLO), VDD Over-Voltage Protection (VDD OVP), over load protection, input under / over voltage protection, internal Over-Temperature Protection (OTP), and cycle-by-cycle current limitation.