ST7070 View Datasheet(PDF) - Sitronix Technology Co., Ltd.
Part Name
Description
MFG CO.
'ST7070' PDF : 51 Pages View PDF
ST7070
Supply Voltage for LCD Drive
There are different voltages that supply to ST7070’s pin (V0 – V4) to obtain LCD drive waveform. We could use
the register command (Ra1,Ra0) to set up the Internal or External Bias Resister. The relations of the bias, duty
factor and supply voltages are shown as below. External Bias Resistor could set up to 1/4 bias and 1/5 bias,
but Internal Bias Resistor only could set up to 1/5 bias.
External
Resistor
Supply Voltage
Bias Resistor Select
V0
V1
V2
V3
V4
1/8
1/4
Ra1=0,Ra0=0
VLCD
3/4VLCD
1/2VLCD
1/2VLCD
1/4VLCD
Duty Factor
Bias
1/8,1/16
1/5
Ra1=0,Ra0=0
VLCD
4/5VLCD
3/5VLCD
2/5VLCD
1/5VLCD
V0
V1
V2
V3
V4
1/4 bias
(1/8 duty cycle)
+5V
VR
R
R
R
R
VLCD
Vss
V0
V1
V2
V3
V4
1/5 bias
(1/16 duty cycle)
+5V
VR
R
R
R
VLCD
R
R
Vss
V1.4
33/51
2009/04/29
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