What happens if I power up the display but do not clock in data for several seconds or longer?
A. There are two things about power sequencing that are very important. You must be careful about how you apply power. Typically, you must turn on the Vcc supply voltage, then within 10-20 milliseconds apply all of the data signals including the data bits, sync signals and clocks. If you apply the data signals before you apply power, you get into a latch-up condition. The LCD looks like a CMOS device that can draw high current if a signal is applied to the gate before Vcc is turned on. Most Sharp LCDs have ESD protection diodes. This makes the potential of a high current path to ground from the signal lines if Vcc is not applied before the data signals. A second problem can occur if you apply power and wait too long before you apply data. This can be a more subtle error. The display needs an AC signal to function properly. If only a DC signal is applied, damage can occur. Generally the damage occurs slowly and is a function of duration, temperature and other conditions, but the effect
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