What do these symbols mean in electronics?

 

[math]V_{DDH}[/math]

[math]V_{DDL}[/math]

[math]V_{SSH}[/math]

[math]V_{SSL}[/math]

Some context would be useful, it could be just about anything.

Some context would be useful, it could be just about anything.

 

This is in the context of liquid crystal display drivers.

I've never seen them in a LC context and without knowing more couldn't even guess at what they mean.

I think it means:

 

VDDH = voltage drain drain high

VDDL = voltage drain drain low

VSSH = voltage source source high

VSSL = voltage source source low

Perhaps reading the manufacturers datasheet for the LCD driver would help? Really when you have an IC with perhaps dozens of connections to the circuit, these could mean anything.