LC75835W Datasheet, PDF (30/35 Pages) Sanyo Semicon Device – CMOS IC 1/3, 1/4-Duty General-Purpose LCD Display Driver

LC75835W
Notes on Controller Transfer of Display Data
Since the LC75835W accepts the display data (D1 to D272) divided into 12 separate transfer operations when using 1/4
duty drive scheme and data (D1 to D210) divided into 9 separate transfer operations when using 1/3 duty drive scheme,
we recommend that the applications transfer all of the display data within a period of less than 30ms to prevent
observable degradation of display quality.
Generation of Buzzer Control Signal
A square wave with a 50% duty ratio is output from the general-purpose output port selected for the output of the
buzzer control signal between the start and end of the buzzer control signal output. If, for example, general-purpose
output port P1 has been selected as the output of the buzzer control signal (PC1 = “0”, PS1 = “1”), the waveform shown
below will be output.
Tz
Tz
Tz
Tz
Tz/2 Tz/2 Tz/2 Tz/2
Tz/2 Tz/2 Tz/2 Tz/2
P1
Beginning of buzzer control signal generation
(Send control data PZ0, PZ1, PZ2, PZ3, PZ4 ("1,0,0,0,0"))
End of buzzer control signal generation
(Send control data PZ0, PZ1, PZ2, PZ3, PZ4 ("0,0,0,0,0"))
Control data PZF
Buzzer control signal frequency fz(=1/Tz)[Hz]
0
fosc/144, fCK/16
1
fosc/72, fCK/8
Note: fosc: Internal oscillation frequency (295 [kHz] typ.), fCK: External clock operating frequency
(32.8 [kHz] typ.)
Oscillation Stabilization Time of the Internal Oscillation Circuit
It must be noted that the oscillation of the internal oscillation circuit is unstable for a maximum of 100µs (oscillation
stabilization time) after oscillation has started.
Internal oscillation
circuit
Oscillation stopped
Oscillation
stabilization time
(100 [µs] max.)
Oscillation operation
(under normal conditions)
<Oscillation start>
1. If the INH pin status is switched from “L” to “H”
when control data OC = “0” and BU = “0”
2. If the control data BU is set from “1” to “0”
when INH = “H” and control data OC = “0”
No.A0429-30/35