LC75847T Datasheet, PDF (21/27 Pages) Sanyo Semicon Device – 1/3, 1/4 Duty General-Purpose LCD Driver

LC75847T
The INH pin and Display Control
Since the IC internal data (1/3 duty: the display data D1 to D318 and the control data, 1/4 duty: the display data D1 to
D420 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 S105, COM1 to COM3, and
COM4/S106 to the V_SS 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 3 and 4.)
Notes on the Power On/Off Sequences
Applications should observe the following sequences when turning the LC75847T power on and off.
• At power on: Logic block power supply (V_DD) on → LCD driver block power supply (V_LCD) on
• At power off: LCD driver block power supply (V_LCD) off → Logic block power supply (V_DD) 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.
• 1/3 duty
t1
VDD
t2
t3
VLCD
INH
CE
D1 to D108,
Internal data ^{P0 to P3, CT0 to CT2,}
DR, DT, FC, SC, BU
Internal data (D109 to D213)
Display and control data transfer
Undefined
VIL
tc
VIL
Defined
Undefined
Defined
Undefined
Undefined
Internal data (D214 to D318)
Undefined
Figure 3
Defined
Undefined
Notes:
t1 ≥ 0
t2 > 0
t3 ≥ 0 (t2 > t3)
tc .......10µs min.
No. 7389-21/27