STE2004 STMicroelectronics, STE2004 Datasheet - Page 7

• Manufacturer Part Number: STE2004
• Description: 102 x 65 SINGLE CHIP LCD CONTROLLER/DRIVER
• Manufacturer: STMicroelectronics

Figure 4. Master Slave Logic Connection with frame Synchronization
Figure 5. Master Slave Logic Connection without frame Synchronization
3.5 Bias Levels
To properly drive the LCD, six (Including VLCD and VSS) different voltage (Bias) levels are generated.
The ratios among these levels and VLCD, should be selected according to the MUX ratio (m). They are
established to be (Fig. 6):
Figure 6. Bias level Generator
thus providing an 1/(n+4) ratio, with n calculated from:
For m = 65, n = 5 and an 1/9 ratio is set.
For m = 49, n =4 and an 1/8 ratio is set.
The STE2004 provides three bits (BS0, BS1, BS2) for programming the desired Bias Ratio as shown below:
VDD1AUX
VDD1AUX
V
LCD
STE2004
STE2004
OSCIN FRIN
OSCIN FRIN
n
------------ - V
n
+
+
3
4
OSCOUT
OSCOUT
LCD
,
n
------------ - V
n
nR
R
R
R
R
+
+
FROUT
FROUT
2
4
n
=
LCD
m 3
VDD1AUX
,
V
n + 3
n + 4
n + 2
n + 4
n + 4
n + 4
V
------------ - V
n
LCD
2
1
SS
–
2
+
FRIN
·V
·V
·V
·V
D00IN1150
4
LCD
LCD
LCD
LCD
STE2004
STE2004
OSCIN
OSCIN
LCD
FRIN
,
------------ - V
n
1
+
OSCOUT FROUT
OSCOUT FROUT
4
LCD
,V
SS
LR0219
LR0220
STE2004
7/66