UPD161622 NEC, UPD161622 Datasheet - Page 38

• Manufacturer Part Number: UPD161622
• Description: 396 OUTPUT TFT-LCD SOURCE DRIVER
• Manufacturer: NEC

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5.6 Rectangular Signal Generator
pin, and a wave of 0 to V
LCD can be generated by connecting an external circuit as shown in Figure 5–21.
5.7 Reference Voltage Generator (VBGR)
generates a constant voltage from V
operational amplifier that adjusts the center level of the COMMON drive output, via a D/A converter.
affected by fluctuations in the supply voltage.
show in Figure 5–21.
the operational amplifier that adjusts the center level of the COMMON drive output.
5.8 D/A Converter Circuit
for the voltage regulator. This D/A converter divides the constant voltage generated by the reference voltage
generator (VBFR) by 256, and a level of voltage between VBGR and V
electronic volume register (R29).
VCOM electronic volume register (R29) is 00H, the set statuses of the DAC
should be connected to V
38
The
This circuit generates a common rectangular signal. A rectangular wave of 0 to V
The
By using this voltage, therefore, the center level of the COMMON drive output can be kept constant, without being
The common output waveform necessary for driving an LCD can be generated by connecting the external circuit
When the internal reference voltage generator is not used (R25: BGRS = 1), directly input the reference voltage to
In addition, this D/A converter also has a function to select a level by using an external pin. If the set value of the
When DACn pin input is valid (R29 = 00H), these pins are pulled up internally , so only the pins that are to be set to L
FEH
00H
01H
02H
03H
FFH
PD161622 is provided with an internal D/A converter to adjust the voltage of the reference voltage generator
PD161622 has a reference voltage generator for the voltage regulator. This reference voltage generator
DAC
EV
0
0
0
0
1
1
7
7
Table 5–9.
DAC
EV
CC1
0
0
0
0
1
1
SS
6
6
.
(V) is output from the VCOUT2 pin. The common output wave necessary for driving an
DAC
Setting of VCOM Electronic Volume Register (R25: BGRS = 0)
EV
0
0
0
0
1
1
5
CC1
5
. The constant voltage generated by this circuit is connected to the input of the
DAC
EV
0
0
0
0
1
1
4
4
Data Sheet S15649EJ2V0DS
DAC
EV
0
0
0
0
1
1
3
3
DAC
EV
0
0
0
0
1
1
2
2
SS
DAC
EV
can be selected by setting the VCOM
0
0
1
1
1
1
7
1
1
to DAC
DAC
S
EV
0
1
0
1
0
1
(V) is output from the VCOUT1
0
0
pins are valid.
0
DACn set
value
255
256
0
2
3
4
PD161622
Remark
DACn
R29