Direct Type/ Local Dimming (Conventional TV power + Boost + LED driver)
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In this topology, the UCC28051 is a boost transition mode (TM) power factor corrector (PFC), which can rectify an AC input line voltage to 380V DC; the resonant LLC stage UCC25600 regulates the output to 24V/2A for an audio amplifier with feedback to the LLC controller, and 48V for the LED driver input. The flyback with UCC28610 in parallel generates 5V/3A for the system board and 5V/1A for standby power. In the LED driver stage, the 48V input voltage requires another front end boost stage to boost the output voltage to 80V, which connects to the eight-channel TLC5960 with 20LEDs at 120mA per string.This technique is the most common type of current LED backlight; the LLC design is easily implemented. The intelligent headroom voltage monitor (oriHVM™) automatically minimizes the power loss caused by the LED forward voltage change. Only a single additional resistor regulates the boost dc-dc output voltage.