LC75897PW Datasheet, PDF (27/34 Pages) Sanyo Semicon Device – 1/3, 1/4-Duty General-Purpose LCD Display Driver

The INH pin and Display Control
LC75897PW
Since the IC internal data (1/3 duty: the display data D1 to D387 and the control data, 1/4 duty: the display data D1 to
D512 and the control data) is undefined when power is first applied, applications should set the INH pin low at the same
time as power is applied to turn off the display (This sets the S1/P1 to S8/P8, S9 to S128, COM1 to COM3, and
COM4/S129 to the VSS level.) and during this period send serial data from the controller. The controller should then set
the INH pin high after the data transfer has completed. This procedure prevents meaningless displays at power on. (See
Figures 5 and 6.)
Notes on the Power On/Off Sequences
Applications should observe the following sequences when turning the LC75897PW power on and off.
(See Figures 5 and 6)
• At power on: Logic block power supply (VDD) on → LCD driver block power supply (VLCD) on
• At power off: LCD driver block power supply (VLCD) off → Logic block power supply (VDD) off
However, if the logic and LCD driver block use a shared power supply, then the power supplies can be turned on and
off at the same time.
1. 1/3 duty
t1
VDD
t2
t3
VLCD
INH
CE
W10 to W15, W20 to W25, W30 to W35,
PC1 to PC8, PS10, PS11, PS20,
Internal data PS21, PS30, PS31, PS40, PS41,
PS5 to PS8, CT0 to CT2, DR, DT, OC,
FC0 to FC2, PF0 to PF2, SC, BU
Internal data (D1 to D129)
Display data and control data transter
Undefined
VIL1
tc
VIL1
Defined
Undefined
Defined
Internal data (D130 to D258)
Undefined
Defined
Internal data (D259 to D387)
Undefined
Defined
Undefined
Undefined
Undefined
Undefined
Note: t1≥0
t2>0
t3≥0 (t2>t3)
tc⋅⋅⋅10µs min
Figure 5
No.A0549-27/34