LC75809PT
www.onsemi.com
41
Notes on Controller Transfer of Display Data
When using the LC75809PT in 1/4 duty, applications transfer the display data (D1 to D352) in four operations,
and in 1/3 duty, they transfer the display data (D1 to D267) in three operations. In either case, applications
should transfer all of the display data within 30 ms to maintain the quality of displayed image.
S89/OSCI Pin Peripheral Circuit
(1) Internal oscillator operating mode (control data OC=0)
Connect the S89/OSCI pin to the LCD panel when the internal oscillator operating mode is selected.
(2) External clock operating mode (control data OC=1)
When the external clock operating mode is selected, insert a current protection resistor Rg (2.2 to 22k) between
the S89/OSCI pin and external clock output pin (external oscillator). Determine the value of the resistance according
to the allowable current value at the external clock output pin. Also make sure that the waveform of the external
clock is not heavily distorted.
(3) Unused pin treatment
When the S89/OSCI pin is not to be used, select the internal oscillator operating mode (setting control data OC to 0)
to keep the pin open.
P1 to P12 Pin Peripheral Circuit
It is recommended the circuit shown below be used to adjust the brightness of the LED backlight using the PWM output
P1 to P12
OSCI/S89
External clock output pin
Rg
External oscillato
Note : Allowable current value at external clock output pin >
V
DD
Rg
OSCI/S89
To LCD panel
OSCI/S89
OPEN
P1 to P12
LED
+5V
