S1D16501 Series
3–12
EPSON
Rev.1.0
V
DD
V
SS
V
DD
V
SS
Powern ON
t
t
t
t
3
5
2
V
Power OFF
t
1
t t t
1 2
3
0s
>
=
V
DSPOFF
10. LCD DRIVE POWER
Each voltage level forming method
To obtain each voltage level for LCD driving, it is optimum to divide the resistance of potential between V
DDH
and GND to drive the LCD using the voltage follower with an operational amplifier.
In taking into consideration of such a case using the operational amplifier, the maximum potential level V
0
for LCD driving has been made a separate pin from V
DD
.
When no operational amplifier is used in V
0
, set V
0
= V
DD
.
When a resistive divider is used, set it to a resistance value as low as possible in the system power capacity.
When a series resistance exists in the power supply line of V
DD
, a voltage drop of V
DD
occurs at the LSI power
supply pin, the relationship with the LCD’s intermediate potential (V
DD
≥
V
0
≥
V
1
≥
V
4
≥
V
5
) cannot be met,
this causing the LSI to be broken down in some cases. When a protection resistor is inserted, it is necessary
to stabilize the voltage by capacitance.
Note in power ON/OFF
Since this LSI is high in the voltage of LCD driving system, when a high voltage is applied to the LCD driving
system with the logic system power supply kept floating or above V
SS
= –2.5 V, an overcurrent flows and LSI
breaks down in some cases.
To avoid this, it is recommended to suppress the potential of LCD drive output to V
0
level using the display
off function (DSPOFF) until the LCD driving system voltage is stabilized.
Be sure to follow the power ON/OFF sequence as shown below:
At power ON ... Logic system ON
→
LCD driving system ON or simultaneous ON of the both
At power OFF ... LCD driving system OFF
→
Logic system OFF or simultaneous OFF of the both
For a countermeasure to such overcurrent, it is effective to put a high-speed melting fuse or protection resistor
in series with the LCD power unit.
It is then required to select the optimum value in the protection resistance according to the capacitance of LC
cell.
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Summary of Contents for S1D16000 Series
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Page 7: ...S1D16006 Series Rev 2 1 www DataSheet4U com ...
Page 23: ...S1D16400 www DataSheet4U com ...
Page 38: ...S1D16501 Rev 1 0 www DataSheet4U com ...
Page 53: ...S1D16700 Rev 1 1 www DataSheet4U com ...