t6963c lcd controller

[mikeb]

hi im trying to use a graphics display that uses the t6963c controller,this ic lists pin#2 as the negative supply for lcd driving, whne i connect the display to the hc11 with this pin disconnected i measure +4.82 volts but the pin is supose to be an input for lcd drive and and a negative voltage of _12 is suppose to be applied here. has anyone worked with this controller or have any knowledge as to what the problem may be. as the display has el backlighting and a pos an negative connection for connecting to the el lamp for backlite purposes when i connect the pos to +5 volts an neg. to gnd the display does not have any type of backlighting. does any one know what could be cauing this problem as well. the display is new i recewntly purchased it and at first i only connected to the el baclight to see if it ould light and it wouldnt. any help will be appreciated.

[dyarker]

The T6963c spec sheet (1.25MB) says pin 2 is RESET. +4.82V is about right for a pin with internal pullup. Maybe the controller manufacturer meant pin 2 of the board the IC is mounted on????<p>Later -<p>[ July 01, 2004: Message edited by: Dale Y ]</p>

[mikeb]

i actually stated that wrong pin#2 for the lcd drive is on the 40 pin connector that interfaces the lcd, pin#2 at the controller is at pin#15 on the interface connector. im having quite a few problems trying to get this display working, with the +4.82 volts at the negative lcd drive input 1 or 3. a techie freind of mines stated the following:<p>If the LCD spec says to connect it to -12v, I would do that. This would be the
'bias' or contrast input to the LCD, which requires a negative voltage. Any
positive voltage you read on this pin is probably due to leakage in the
internal circuits of the LCD driver. If you don't connect this pin to a
negative supply, the dots on the lcd panel will not turn on.<p>Some LCD controllers have an internal inverter, or they reference the display
to the +5V input instead of ground to avoid having to use a negative supply.<p>