各位大虾:
小弟正在做一个koppin LCD的驱动板,说明书上关于电源供电有以下一段话:
"this AMLCD requires four supply voltages : VDD,VEE,VREF, and VSS(VSS=0V). The display's internal circuits are powered by the VDD,VEE,VREF, and VSS supplies, with most operating current flowing from VDD to VEE. VREF is a reference voltage used by the inte**ce circuits; it will normally be set to one-half the high logic level.
The VCOM pin is tied to the pixel arraly's common electrode, a large capacitive load . it also sets the white level for the Vid high and Vid low amplifiers. Although VCOM ideally draws zero current ,it does require a low impedence drive to handle transients."
我所有的电压都是从LT1736得到,
VDD 11V (LT1736输入12V,调压输出11V); VCOM 6.5V (LT1736输入12V,调压输出6.5V); ;VEE 2V(LT1736输入3.3V,调压输出2V);VREF 1.65V(LT1736输入3.3V,调压输出1.65V);
从说明书上看,有电流从VDD向VEE流!这样导致我一加上屏,VEE电压就被抬高!而且导致LT1736损坏!请问怎样才能保证VEE在2V呢?
有朋友建议我用TL431 还有朋友建议就用3个二极管串起来限压!可行么?
另外最后一句话说:VCOM需要一个低阻抗驱动,请问怎么得到? |