LC75897PW Datasheet, PDF (29/34 Pages) Sanyo Semicon Device – 1/3, 1/4-Duty General-Purpose LCD Display Driver

LC75897PW
Notes on Controller Transfer of Display Data
Since the LC75897PW accepts the display data (D1 to D387) divided into three separate transfer operations when using
1/3 duty drive scheme and the data (D1 to D512) divided into four separate transfer operations when using 1/4 duty
drive scheme, we recommend that applications transfer all of the display data within a period of less than 30ms to
prevent observable degradation of display quality.
OSC pin peripheral circuits
(1) RC oscillator operating mode (control data OC = 0)
When RC oscillator operating mode is selected, an external resistor Rosc and an external capacitor Cosc must be
connected between the OSC pin and GND.
Rosc
OSC
Cosc
(2) External clock operating mode (control data OC = 1)
When selecting the external clock operating mode, connect a current protection resistor Rg (2.2 to 22kΩ) between
the OSC pin and the external clock output pin (external oscillator). Determine the value of the resistance according
to the maximum allowable current value of the external clock output pin. Also make sure that the waveform of the
external clock is not excessively distorted.
External clock output pin
External oscillator
OSC
Rg
Note:
Allowable current value at external clock output pin >
VDD
Rg
P1 to P3 pin peripheral circuit
It is recommended the circuit shown below be used to adjust the brightness of the LED backlight using PWM output
ports P1 to P3.
+5V
LED
P1 to P3
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