ST7781
11.1.13 Power Control 2 (R11h)
Power Control 2 (R11h)
RS
/WR
/RD D15 D14 D13 D12 D11 D10
D9
DC1
1
D8
DC1
0
D7
0
D6
DC0
2
D5
DC0
1
D4
DC0
0
D3
0
D2
VC
2
D1
VC1
0
D0
VC0
0
DC1
0
0
0
0
0
0
0
0
0
0
1
↑
1
2
1
1
1
0
1
1
1
0
0
Default value
DC0 [2:0]: Selects the operating frequency of the step-up circuit 1. The higher step-up operating frequency enhances
the drivability of the step-up circuit and the quality of display but increases the current consumption.
Adjust the frequency taking the trade-off between the display quality and the current consumption into
account.
DC1 [2:0]: Selects the operating frequency of the step-up circuit 2. The higher step-up operating frequency enhances
the drivability of the step-up circuit and the quality of display but increases the current consumption.
Adjust the frequency taking the trade-off between the display quality and the current consumption into
account.
Step-Up Circuit 1
Step-Up Circuit 2
DC0[2:0]
DC1[2:0]
Step-Up Frequency ( fDCDC1
)
Step-Up Frequency ( fDCDC2
)
000
001
010
011
100
101
110
111
Fosc/4
Fosc/8
Fosc/16
Fosc/32
Fosc/64
000
001
010
011
100
101
110
111
Fosc/8
Fosc/16
Fosc/32
Fosc/64
Fosc/128
Fosc/128
Fosc/256
Halt step-up circuit 1
Fosc/256
Fosc/512
Description
Halt step-up circuit 2
Note: Be sure
fDCD1 ≥ fDCDC2 when setting DC0[2:0] and DC1[2:0]
VC [2:0] Sets the ratio factor of VDD to generate the reference voltages Vci1.
VC[2:0]
000
001
010
011
100
101
110
Vci1 voltage
0.95 X VDD
0.90 X VDD
0.85 X VDD
0.80 X VDD
0.75 X VDD
0.70 X VDD
Disable
111
1.0 X VDD
Ver. 1.7
55
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