LC75890W Datasheet, PDF (29/32 Pages) Sanyo Semicon Device – 1/4duty and Static Drive General-Purpose LCD Display Drivers

LC75890W, LC75890E
S37/OSCI Pin Peripheral Circuit
(1) Internal oscillator operating mode (control data OC=0)
Connect the S37/OSCI pin to the LCD panel when the internal oscillator operating mode is selected.
OSCI/S37
To LCD panel
(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 22kΩ) between
the S37/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.
In addition, the following conditions must be met : VDD≤VLCD.
External clock output pin
External oscillator
OSCI/S37
Rg
Note: Allowable current value at external clock output pin >
VDD≤VLCD
VLCD
Rg
(3) Unused pin treatment
When the S37/OSCI pin is not to be used, select the internal oscillator operating mode (setting control data OC to 0)
to keep the pin open.
OSCI/S37
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
+5V
LED
P1 to P12
Note : In the case of the LC75890E(QIP44M), the output pins are effective for only P1 to P11 pins.
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