ST7578
Set V0:
A0
R/W(RWR)
D7
D6
D5
D4
D3
D2
D1
D0
0
0
1
VOP6
VOP5
VOP4
VOP3
VOP2
VOP1
VOP0
The operation voltage V0 can be set by software.
V0=( a + VOPx X b )
(1)
The parameters are explained in table 4. The maximum voltage that can be generated is depending on the VDD2 voltage
and the display load current. Two overlapping V0 ranges are selectable via the command “Set V0 Range”. For the lower
range (PRS=0), a=a1 and for the higher range (PRS=1), a=a2. The voltage steps in both ranges are equal to “b”. Note that
the internal booster is turned off if VOP[6:0] and the PRS bit are all set to zero.
* The Vop must be operated in the range of 4V to 9.5V for the normal or partial display mode application, so that
customer have some range(<4V; >9.5V) to adjust contrast by themselves.
Table 4 Typical values for parameter for the HV-Generator programming
SYMBOL
VALUE
2.94 (PRS=0)
6.75 (PRS=1)
0.03
UNIT
a1
a2
b
V
V
V
VOP[6:0] (programmed) {00 hex… 7F hex}
Fig 15. Setting V0 Voltage
Ver 1.2
31/52
2007/04/30
SITRONIX [ SITRONIX TECHNOLOGY CO., LTD. ]
