【摘要】 设计了一种用于白光LED(WLED)驱动器且具有PWM调光和模拟调光两种工作模式的升压控制电路.电路中,大电容补偿网络的引入和低电压提取电路的设计有效地提高了电路调光性能.利用0.5μm-BCD工艺库仿真,结果表明:PWM调光下,控制电路在零负载与额定负载之间快速切换,切换时间小于12μs;模拟调光下,输出与调光电压实现自适应,支路电流为20mA时,WLED阵列为6×6、6×8、6×10,输出分别稳定在20.4V、27.0V和33.3V.该设计改善了WLED驱动器的调光比,进而提升LCD显示质量.更多还原

【Abstract】 The paper presents a step-up controller that is used in WLED driver system and has two dimming modes:PWM dimming mode and Analog dimming mode.In the circuit,the introduction of large capacitor compensating network and the design of low voltage choose circuit effectively improve the circuit dimming performance.System simulation of the step-up controller is simulated in 0.5μm-BCD process.The simulation results show that:The step-up controller can switch between zero load and rated load in PWM dimming mode,the switching time is less than 12μs;Output voltage is adaptive to the dimming voltages in analog dimming mode,when the load is 6×6,6×8,6×10WLED array,the output stabilizes at 20.4V,27Vand 33.3V,and the LED current is set to 20mA.This design improves the WLED driver dimming performance,and thus enhances the quality of the LCD display.更多还原