S1D15715 Epson Electronics America, Inc., S1D15715 Datasheet - Page 32

• Manufacturer Part Number: S1D15715
• Description: Liquid Crystal Display =lcd Driver
• Manufacturer: Epson Electronics America, Inc.

S1D15715 Series Technical Manual
<Setting example: When setting T
When the intermediate resistor values (D4, D3, D2, D1, D0) = (1, 0, 0, 0, 0) are selected from the electronic
volume, the following is given by expression B-1 since α = 15 and V
If you select 5µA for the current conducted to Ra’ and Rb’, the following expression is derived:
Thus, the following is derived from expressions B-2 and B-3:
Table 15 shows the command selected from the electronic volume. Table 16 lists V
and pitch width available from the electronic volume function.
(C) When using external resistors (When using variable resistors instead of the V
26
V
Electronic volume
0
[ ]: Commands selected from the electronic volume.
voltage regulator internal resistance ratio
When using the above external resistor, LCD voltage V
finely tune Ra’ and Rb’.
In this case too, using the electronic volume function permits you to control an LCD voltage V
the command and, thus, adjust the contrast of LCD display.
The V
(variable resistors) and R3 within the range of |V
V
10 (T
Variable range
Pitch width
resistors)
REG
a
is the constant voltage source in the IC and its value remains at a constant level as shown in Table
=25°C).
0
V
voltage can be obtained from the following expression by setting external resistors R1, R2
0
Rb'
Ra'
∴Ra’＝220kΩ, Rb’=1180kΩ
Content
V
7V=(1+ Rb’/Ra’)･(1-15/200)･1.2
Ra’＋Rb’＝1.4MΩ
Rb’/Ra’＝5.31
V
0
0
=(1+ Rb’/Ra’)･(1-α/200)･V
={1+ (R3+R2-∆R2) / (R1+∆R2)}･V
={1+ (R3+R2-∆R2) / (R1+∆R2)}･(1-α/200)･V
[V
External
resistor R2
External
resistor R3
External
resistor R1
EV
6.45[80H]
=(1-α/200)･V
Min.
a
=25°C and V
∆R1
V
R
to
REG
0
=7V>
]
V
D7
0
1
EV
Table 15
Table 16
+
-
7.0[90H]
Fig.13
EPSON
REG
(Constant voltage source + electronic volume)
Typ.
38.4
0
|<|V
D6
0
0
OUT
EV
0
| and finely tuning R2 (∆R2):
can also be set by adding a variable resistor to
D5
REG
1
0
(Expression B-2)
(Expression B-3)
to
= 1.2V (Expression B-2).
REG
D4
7.64[9FH]
0
1
Register
Max.
V
V
D3
0
SS
0
0
0
voltage regulator internal
(Expression C-1)
0
voltage variable range
D2
1
0
[mV]
Unit
[V]
D1
1
0
0
through
Rev.1.0
D0
1
0