PCF8576 Philips Semiconductors, PCF8576 Datasheet - Page 9

• Manufacturer Part Number: PCF8576
• Description: Universal LCD driver for low multiplex rates
• Manufacturer: Philips Semiconductors

Philips Semiconductors
6.4
6.4.1
The static LCD drive mode is used when a single
backplane is provided in the LCD. Backplane and
segment drive waveforms for this mode are shown in
Fig.4.
6.4.2
When two backplanes are provided in the LCD, the 1 : 2
multiplex mode applies. The PCF8576 allows use of
1
1998 Feb 06
2
bias or
Universal LCD driver for low multiplex
rates
V
V
V
V
off(rms)
state1
on(rms)
state2
LCD drive mode waveforms
t ( )
t ( )
S
1 : 2
1
=
=
TATIC DRIVE MODE
=
=
3
0 V
V
bias in this mode as shown in Figs 5 and 6.
V
V
op
S
S
MULTIPLEX DRIVE MODE
n
n
t ( ) V
+
1
t ( ) V
–
–
BP0
BP0
t ( )
t ( )
Fig.4 Static drive mode waveforms (V
state 1
state 2
S n 1
BP0
S n
V LCD
V LCD
V LCD
V op
V DD
V DD
V DD
V op
V op
V op
0
0
(b) resultant waveforms
(a) waveforms at driver
at LCD segment
9
T frame
6.4.3
When three backplanes are provided in the LCD, the 1 : 3
multiplex drive mode applies, as shown in Fig.7.
6.4.4
When four backplanes are provided in the LCD, the 1 : 4
multiplex drive mode applies, as shown in Fig.8.
op
state 1
1 : 3
1 : 4
(on)
LCD segments
= V
MBE539
DD
MULTIPLEX DRIVE MODE
MULTIPLEX DRIVE MODE
V
state 2
(off)
LCD
).
Product specification
PCF8576