The PLC810PG is a combined PFC and LLC off-line controller with integrated high voltage half-bridge drivers. Figure 1 shows a simplifi ed schematic of a PLC810PG based power supply where the LLC resonant inductor is integrated into the Figure 1. Typical Application Circuit – LCD TV Power Supply. transformer. The PFC section of the PLC810PG is a universal input continuous current mode (CCM) design that does not require a sinusoidal input reference, thereby reducing system cost and external components. The DC-DC controller drives an LLC resonant topology. This variable frequency controller provides high effi ciency by switching the power MOSFETs at zero voltage, eliminating most switching losses. The LLC controller is built around a current controlled oscillator with a control range selected to support the traditional frequency of operation found in televisions. To ensure zero voltage switching, the dead time of the LLC switching in the PLC810PG is tightly toleranced and can be adjusted with an external resistor. The highside/lowside duty cycle is also closely matched to provide balanced output currents reducing output diode cost. A typical PLC810PG LLC design operates at 100 kHz (under normal conditions). Depending on the LLC circuit design, the switching swit frequency can vary from half to three times the nominal operating frequency as a result of line and load changes.