Powerint 公司的PLC810PG 是集成了半桥驱动器的PFC和LLC离线控制器,其中的PFC部分是通用输入连续电流模式(CCM),不需要正弦输入参考,从而降低成本和外接元件.LLC控制器采用电流控制振荡器,控制范围可选择以支持电视的传统工作频率.主要应用32-60吋LCD TV电源,150-600W电源和LED街灯照明.本文介绍PLC810PG主要特性, 方框图, 典型应用电路,包括LCD TV 电源, PFC电路控制输入和LLC级, 输入电路和PFC功率级和待机电源电路图.
The PLC810PG is a combined PFC and LLC off-line controller with integrated high voltage half-bridge drivers. 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 efficiency 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 nominal conditions). Depending on the LLC circuit design, the switching frequency can vary from half to three times the nominal operating frequency as a result of line and load changes.
The PFC converter is frequency locked to the LLC to minimize noise and electromagnetic interference. Increasing the PFC frequency in synchronization with the LLC at light loads reduces the current at which the PFC boost converter becomes discontinuous improving light load operation and reducing power line harmonics. PFC and LLC primary side fault management is provided.
The phase of the PFC PWM output is dynamically adjusted relative to the LLC phase such that the switching edges do not coincide with noise sensitive events in the PWM and LLC timing circuits. This edge-collision avoidance technology simplifies power supply layout and improves performance. Phase synchronization reduces EMI spectral components and reduces ripple current in the PFC capacitor.
PLC810PG主要特性:
• Highly integrated, eliminates external components
• Frequency and phase synchronized PFC and LLC
• Reduced noise and EMI
• Ripple current reduction in PFC output capacitor
• Edge collision-avoidance simplifies layout
• Comprehensive PFC and LLC fault handling and current limiting
• Proprietary continuous conduction mode PFC for high efficiency with low component cost
• High efficiency Zero Voltage Switching (ZVS) LLC
• Off-time PFC control eliminates AC input sensing components
• Configurable, precise dead time control and frequency limit
• Prevents hard MOSFET switching
• Tight LLC duty cycle symmetry for balanced O/P diode currents
• Lead and halogen free Green package
PLC810PG 应用:
• 32” to 60” LCD TV power supplies
• Off-line 150 W to 600 W efficiency-optimized power supplies
• LED street lighting
图1.PLC810PG方框图
图2. PLC810PG 典型应用电路– LCD TV 电源
图2. PLC810PG LCD TV 电源应用电路– PFC电路控制输入和LLC级
图3. PLC810PG LCD TV 电源应用电路–输入电路和PFC功率级
图4. PLC810PG LCD TV 电源应用电路– 待机电源
来源:电子设计应用 作者: 时间:2009/12/2 0:00:00
