HT0313A Tomato LSI, Inc., HT0313A Datasheet - Page 26

• Manufacturer Part Number: HT0313A
• Description: 65COM/132SEG DRIVER & CONTROLLER FOR STN LCD
• Manufacturer: Tomato LSI, Inc.

HT0313A
b. Voltage regulator circuits
The function of the internal voltage regulator circuits is to determine liquid crystal operating voltage, V0, by
the adjusting resistors, Ra and Rb, within the range of |V0| < |VOUT|. Because VOUT is the operating
voltage of operational-amplifier circuits as shown in figure 6-13, it is necessary to be applied internally or
externally.
For the equation 1, we determine V0 with Ra, Rb and V
via INTRS pin. The voltage of electronic volume, V
voltage parameter
to 63. Refer to table 6-7. VREF voltage at T
TOMATO LSI Inc.
Table 6-7. Electronic contrast control register (Reference Voltage Parameter : , 64step)
SV5
0
0
1
1
1
:
:
:
:
SV4
0
0
0
1
1
:
:
:
:
65COM / 132SEG DRIVER & CONTROLLER FOR STN LCD
is the value selected by instruction, "Set reference voltage register", within the range 0
SV3
0
0
0
1
1
:
:
:
:
26
SV2
0
0
0
1
1
:
:
:
:
V
V0 = ( 1 +
EV
= (1 -
SV1
0
0
0
1
1
:
:
:
:
( 63- )
300
OPR
Rb
Ra
SV0
=25 C is 2.0V
) x V
0
1
0
0
1
:
:
:
:
) x VREF [V] ------ (Equation 2)
EV
EV,
EV
Reference Voltage
[V] ------ (Equation 1)
is determined by equation 2, where the reference
Parameter ( )
. Ra and Rb are connected internally or externally
32 (default)
3%.
62
63
0
1
:
:
:
:
Maximum
Minimum
V0
:
:
:
:
:
:
:
:
:
:
:
Ver 0.0
Contrast
High
Low
:
:
:
:
:
:
:
:
:
:
: