OM4085 Philips Semiconductors, OM4085 Datasheet - Page 7

• Manufacturer Part Number: OM4085
• Description: Universal LCD driver for low multiplex rates
• Manufacturer: Philips Semiconductors

Philips Semiconductors
LCD drive mode waveforms
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.
When two backplanes are provided in the LCD the 1 : 2 multiplex drive mode applies. The OM4085 allows use of
1
The backplane and segment drive waveforms for the 1 : 3 multiplex drive mode (three LCD backplanes) and for the 1 : 4
multiplex drive mode (four LCD backplanes) are shown in Figs 7 and 8 respectively.
1997 Feb 25
2
handbook, full pagewidth
Universal LCD driver for low multiplex
rates
or
1
3
bias in this mode as shown in Figs 5 and 6.
S n
state 1
state 2
BP0
Fig.4 Static drive mode waveforms: V
S n
1
V op
V op
V DD
V LCD
V DD
V LCD
V DD
V LCD
V op
V op
0
0
(b) resultant waveforms
(a) waveforms at driver
at LCD segment
T frame
7
state 1
(on)
LCD segments
At any instant (t):
V state 1 (t) = V S n (t)
V on(rms) = V op
V state 2 (t) = V S
V off(rms) = 0 V
op
= V
state 2
(off)
DD
n
V
1
LCD
(t)
V BP0 (t)
.
MGG392
V BP0 (t)
Product specification
OM4085