SA8807A
3.
LCD Display
The SA8807A LCD driver is capable of driving a 3 or 4 backplane, 12 digit (7
segment) display, plus decimal points.
In the case of a 4 back plane display, typically the most significant digit is addressed
by columns VS[22] and VS[23] and the least significant digit, by VS[0] and VS[1].
The display segments addressed via the column outputs are given in a typical
configuration below:
The data in memory is constantly being displayed on the liquid crystal display. New
data is displayed as soon as it is latched into memory.
A segment is switched on when the corresponding difference between backplane
VR[ ] and segment VS[ ] outputs is V
DD
, and switched off when switched to 1/3 V
DD
.
The voltage is alternated to avoid a DC voltage on the LCD (See Diagram 2).
The backplane multiplex rate is determined by the clock/oscillator frequency on the
CLK input.
sames
9/14
SAMES [ SAMES ]
