ST7533 Sitronix Technology, ST7533 Datasheet - Page 20

• Manufacturer Part Number: ST7533
• Description: 33 x 96 Dot Matrix LCD Controller/Driver
• Manufacturer: Sitronix Technology

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ST7533
The Power Supply Circuits
The power supply circuits are low-power consumption power
supply circuits that generate the voltage levels required for
the LCD drivers. They are Booster circuits, voltage regulator
circuits, and voltage follower circuits. They are only enabled
in master operation. The power supply circuits can turn the
Booster circuits, the voltage regulator circuits, and the
* The “step-up system terminals” refer CAP1+, CAP1–, CAP2+, CAP2–, and CAP3–.
* While other combinations, not shown above, are also possible, these combinations are not recommended
The Step-up Voltage Circuits
Using the step-up voltage circuits equipped within the ST7533 chips it is possible to product a 2X,3X or 4X step-up of the
4X step-up: Connect capacitor C1 between CAP1+ and CAP1–, between CAP2+ and CAP2–, between CAP1+ and CAP3–,
3X step-up: Connect capacitor C1 between CAP1+ and CAP1–, between CAP2+ and CAP2– and between V
2X step-up: Connect capacitor C1 between CAP1+ and CAP1–, and between V
The step-up voltage relationships are shown in Figure 7
Ver 1.0
V
because they have no practical use.
DD
Only the internal power supply is used
Only the voltage regulator circuit and the
Only the V/F circuit is used
Only the external power supply is used
– V
voltage follower circuit are used
SS2
voltage levels.
and short and shor between CAP3– and
terminal that is 3 times the voltage difference between V
between CAP2–, CAP3– and
the voltage between
and between V
4 times the voltage level between V
Use Settings
Table 7
D2
D1
D0
bit
SS2
The Control Details of Each Bit of the Power Control Set Command
Booster circuit control bit
Voltage regulator circuit control bit (V/R circuit)
Voltage follower circuit control bit (V/F circuit)
and
VDD
VOU
and V
T, to produce a voltage level in the negative direction at the
VOUT
SS
2.
D2
1
0
0
0
to produce a voltage in the negative direction at the
DD
Reference Combinations
D1 D0
and V
1
1
0
0
VOUT
function
Table 8
1
1
1
0
SS
to produce a voltage level in the negative direction at the
20/60
2.
Voltage
booster
ON
OFF
OFF
OFF
voltage follower circuits ON or OFF independently through
the use of the Power Control Set command. Consequently, it
is possible to make an external power supply and the internal
power supply function somewhat in parallel. Table 7 shows
the Power Control Set Command 3-bit data control function,
and
DD
and V
Voltage
regulator
Table
ON
ON
OFF
OFF
SS
SS2
2.
8
and V
Voltage
follower
shows
ON
ON
ON
OFF
OUT
, leave CAP2+ open, and short
“1”
ON
ON
ON
Status
V
reference
OUT
VOUT
External
voltage
input
V5, V
V
OFF
OFF
OFF
VOUT
1
“0”
V
, V
to V
SS2
terminal that Is twice
SS2
SS2
terminal that is
5
SS2
combinations.
Step-up
voltage
and V
2003/07/21
Open
Open
Used
Open
VOUT
OUT
,