LC75890W Datasheet, PDF (27/32 Pages) Sanyo Semicon Device – 1/4duty and Static Drive General-Purpose LCD Display Drivers

LC75890W, LC75890E
Display Control and the INH Pin
Since the LSI internal data (1/4 duty drive : the display data D1 to D148 and the control data, Static drive : the display
data D1 to D37 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 S12/P12, S13 to S36, COM4 to
COM1, and S37/OSCI pins 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 display at
power on.
(See Figure 4 and Figure 5.)
Notes on the Power On/Off Sequences
Applications should observe the following sequences when turning the LC75890 power on and off.
(See Figures 4 and Figure 5.)
• 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)1/4 duty drive
t1
VDD
t2
t3
VLCD
INH
CE
Internal data
BD1 to BD37,BF0 to BF2,
FC0 to FC2,DT,EXF,OC,SC,BU
W10 to W15,W20 to W25,
Internal data W30 to W35,PF0 to PF3,P1A,
P1B to P12A,P12B,P0 to P3
Internal data (D1 to D48)
Undefined
Undefined
Undefined
Display data and control
data transferred
VIL1
tc
VIL1
Defined
Defined
Defined
Undefined
Undefined
Undefined
Internal data (D49 to D96)
Undefined
Defined
Undefined
Internal data (D97 to D148)
Undefined
Defined
Undefined
Note1 : t1≥0
t2>0
t3≥0 (t2>t3)
tc … 10μs min
Note2 : In the case of the LC75890E(QIP44M), the display data are effective for only D1 to D44, D49 to D92,
D97 to D136, and D145 to D148, the display blinking control data are effective for only BD1 to BD11,
BD13 to BD23, BD25 to BD34, and BD37, and the general-purpose output function/PWM output
function switiching control data of the general-purpose output port are effective for only P1A, P1B to
P11A, P11B.
[Figure 4]
No.A1971-27/32