pcf8814 NXP Semiconductors, pcf8814 Datasheet - Page 35

• Manufacturer Part Number: pcf8814
• Description: Pcf8814 65 X 96 Pixels Matrix Lcd Driver
• Manufacturer: NXP Semiconductors

Philips Semiconductors
Table 19 Bias settings
The V
following equations:
Where V
liquid crystal display and N is the number of driven lines.
The relationship between selected MUX-rate, the number
of simultaneously-selected rows (p) and the number of
driven lines is shown in Table 20.
Table 20 Relationship between MUX rate, MUX
When the selected MUX rate, bias system (a) and the
threshold voltage (V
defined, LCD supply voltage (V
2003 Mar 13
V
V
V
BS[2:0]
ON
OFF
LCD
65
000
001
010
011
100
101
110
111
MUX RATE
=
ON
=
=
1:80
1:16
1:24
1:32
1:40
1:48
1:56
1:65
F
-- -
a
ON
2a V
and V
F
-- -
a
mode (p) and number of driven lines (N)
96 pixels matrix LCD driver
is defined by the threshold voltage (V
p
--------------------------------------------
1.075
1.150
1.225
1.300
1.375
1.450
1.525
1.675
p
------------------------------------------- -
OFF
TH
F/G
a
value can be calculated from the
a
2
TH
2
+
N
------------------------------------- -
p a
+
N
) of the liquid crystal display are
N
N 2a
+
2
–
0.15
0.30
0.45
0.60
0.75
0.90
1.05
1.35
+
2a
N
p
2
2
2
2
4
4
4
4
N
+
LCD
2a
) is determined by:
(p = 2)
2.15
2.30
2.45
2.60
2.75
2.90
3.05
3.35
a
16
24
32
40
48
56
68
N
8
TH
(p = 4)
4.3
4.6
4.9
5.2
5.5
5.8
6.1
6.7
) of the
a
35
11.9
11.9.1
V
the on-chip capacitive charge pump.
The Power control instruction may be used to switch V
generation on or off. The Charge pump control instruction
may be used to select the required voltage multiplication
factor. The Set V
the LCD drive voltage V
The generation of V
all factors that effect V
of MMVOPCAL (from OTP) and the 7 bits resulting from
the temperature compensation mechanism. Equations
summarizing all factors are
and
Where:
Table 21 Parameters of V
V
V
As the programming range for the internally generated
V
(9 V), the user has to ensure, while setting the V
register and selecting the temperature compensation,
that under all conditions and including all tolerances
V
Also, because the programming range for the internally
generated V
allowed V
the V
compensation, that under all conditions and including all
tolerances V
LCD
OP
LCD
LCD
LCD
V
programmed V
MMVOPCAL[5:0] is the value of the offset stored in the
OTP cells in twos complement format
V
temperature compensation block (see Table 23)
a and b are fixed constant values (see Table 21).
PR
T
[7:0] in twos complement format comes from the
SYMBOL
may be supplied externally or generated internally by
=
PR
allows values above the maximum allowed V
remains below 9.0 V.
[7:0] is set in the instruction decoder and is the
=
LCD drive voltage
V
V
register and selecting the temperature
LCD
b
a
PR
LCD
OP
+
LCD
LCD
DRIVE VOLTAGE GENERATION
(5 V), the user has to ensure, while setting
MMVOPCAL
b
allows values below the minimum
OP
+
PR
remains above 5.0 V.
a
LCD
instruction is used for programming
register value as an unsigned number
LCD
is illustrated in Fig.34. This shows
CAUTION
LCD.
VALUE
LCD
generation, including the 6 bits
0.03
+
3
V
T
Objective specification
PCF8814
UNIT
V
V
PR
LCD
LCD
(1)
(2)