Recently, I started to design a LC (Liquid Crystal) shutter glass. The question is which component should I use. This is the LC shutter I might use: PolarSpeed®-S
However, there are a few more shutters to test so this shutter is not the only option. Anyway, we need fast switching response (below 100us) and to do that overdriving is essential.
Coming back to the question, this is the usual way to implement overdrive:
you see, applying higher voltage for enough time of period then returning to nominal voltage level makes LC switching faster.
And this is the overdriving method of PolarSpeed®-S:
PolarSpeed®-S uses two cells and this way it achieves below 50 uS rise and fall time.
So I was thinking there must be several ways to apply those voltage levels to LC cells.
1- An analog switch + Linear regulator(3 outputs)
I couldn't find a deMUX in schematic so think those switches as 1:3 deMUX, everything is digital.
the other options are similar also:
2- Several Linear Transistor Driver
3- Several Voltage references + Swicthes
Or, can I:
4- Just use a few Op-Amps + resistors + switch
4- is the easiest and most flexible one because I already have 28V supply and all I will need are 3 Op-Amps, a voltage conterter to < -15V and switch. Also, this might be a good fit because I am allowed to change the gain of the opAmps so I can change the applied voltage to cells via changing resistors that way I can use the same pcb to test several shutters.
But I can not think of anything about pros and cons of those 4 options. So would you help me through this? What is the finest way for LCD overdriving? There may be other options I missed so if you know other options please share. Thanks per advance.
edit: a new idea by ChrisR is added below:
in the schematic GD(Gate driver) supplies are different in tme mean of overdrive purpose. GD1 supply is 14V - 0V, GD2 supply is 8V - 0V and GD3 is 14V - 8V. And just to simplify, diodes forward voltages are 1 V. So if I use this configuration, output will be like:
this I think, but I am not sure. Is this configuration safe to use?