ST7567 View Datasheet(PDF) - Unspecified
Part Name
Description
MFG CO.
'ST7567' PDF : 73 Pages View PDF
ST7565S
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
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 Table 8 shows reference combinations.
Table 7
bit
function
Status
“1” “0”
D2
Booster circuit control bit
D1
Voltage regulator circuit control bit (V/R circuit)
D0
Voltage follower circuit control bit (V/F circuit)
ON OFF
ON OFF
ON OFF
The Control Details of Each Bit of the Power Control Set Command
Use Settings
Only the internal power supply is used
Only the voltage regulator circuit and the
voltage follower circuit are used
Only the V/F circuit is used
Table 8
D2
D1 D0
Voltage Voltage Voltage
booster regulator follower
1 1 1 ON
ON
ON
External
voltage
input
VSS2
0 1 1 OFF
ON
ON
VOUT, VSS2
0 0 1 OFF
OFF
ON
V5, VSS2
Step-up
voltage
Used
Open
Open
Only the external power supply is used
0 0 0 OFF
OFF
Reference Combinations
OFF
V1 to V5
Open
* 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
because they have no practical use.
The Step-up Voltage Circuits
Using the step-up voltage circuits equipped within the
ST7565S chips it is possible to product a 2X,3X,4X,5X or 6X
step-up of the VDD – VSS2 voltage levels.
6X step-up: Connect capacitor C1 between CAP1+ and
CAP1–, between CAP2+ and CAP2–, between
CAP1+ and CAP3–, between CAP2+ and
CAP4–,between CAP1+ and CAP5–, and
between VSS2 and VOUT, to produce a voltage
level in the negative direction at the VOUT
terminal that is 6 times the voltage level
between VDD and VSS2.
5X step-up: Connect capacitor C1 between CAP1+ and
CAP1–, between CAP2+ and CAP2–, between
CAP1+ and CAP3–, between CAP2+ and
CAP4–,and between VSS2 and VOUT, to
produce a voltage level in the negative direction
at the VOUT terminal that is 5 times the voltage
level between VDD and VSS2.
4X step-up: Connect capacitor C1 between CAP1+ and
CAP1–, between CAP2+ and CAP2–, between
CAP1+ and CAP3–, and between VSS2 and
VOUT, to produce a voltage level in the negative
direction at the VOUT terminal that is 4 times the
voltage level between VDD and VSS2.
3X step-up: Connect capacitor C1 between CAP1+ and CAP1–, between
CAP2+ and CAP2– and between VSS2 and VOUT, and short
between CAP3– and VOUT to produce voltages
level in the negative direction at the VOUT
terminal that is 3 times the voltage difference
between VDD and VSS2.
2X step-up: Connect capacitor C1 between CAP1+ and
CAP1–, and between VSS2 and VOUT, leave
CAP2+ open, and short between CAP2–,
CAP3– and VOUT to produce a voltage in the
negative direction at the VOUT terminal that Is
twice the voltage between VDD and VSS2.
The step-up voltage relationships are shown in Figure 7.
Ver 0.3c
31/72
2002/07/22
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