MP4653

The MP4653 is a CC/CV mode LLC TV LED driver for LED backlighting, especially for large size TV LED backlighting. Powered by 9V to 30V input supplies, the MP4653 outputs two 180 degree phase shifted driving signals for the external power stages. Its enhanced 9V gate driver provides adequate driving capability and can directly drive the external MOSFETs through an external gate driving transformer. The MP4653 integrates a constant current control loop for the LED current regulation and also a constant voltage control loop for the DC bus voltage, which is used to generate system power supplies like 12V/5V with other DC/DC converters. The CC/CV control loop programs the operating frequency of the LLC power stage and thus regulates the LED current and also the bus voltage. The MP4653 incorporates both analog dimming and PWM dimming to the LED current. A driving signal is output to directly drive the dimming MOSFET, which helps to achieve fast and high contrast ratio PWM dimming. The PWM dimming signal is also used for the CC/CV mode control. At PWM on interval, the CC mode is effective and the LED current is regulated; at PWM off interval, the CV mode is effective and the DC bus voltage is regulated. The gate driving signal and thus the energy through the power stage are continuous at both the PWM on interval and the PWM off interval. This helps to eliminate the system audible noise at PWM dimming. The MP4653 features sufficient and smart protection to increase system reliability. It protects the fault condition at both the DC bus stage and the LED driver stage. The protection for the DC bus stage includes the over voltage protection and over current protection (short protection).