Philips Semiconductors
Product specification
Universal LCD driver for low multiplex
rates
PCF8566
handbook, full pagewidth
Tframe
VDD
VDD
−
Vop/3
VDD
−
2Vop/3
VLCD
VDD
VDD
−
Vop/3
VDD
−
2Vop/3
VLCD
VDD
VDD
−
Vop/3
VDD
−
2Vop/3
VLCD
VDD
VDD
−
Vop/3
VDD
−
2Vop/3
VLCD
VDD
−
Vop/3
VDD
−
2Vop/3
VLCD
VDD
VDD
−
Vop/3
VDD
−
2Vop/3
VLCD
(a) waveforms at driver
Vop
2Vop/3
Vop/3
state 1
0
−V
op/3
−2V
op/3
−V
op
Vop
2Vop/3
Vop/3
state 2
0
−V
op/3
−2V
op/3
−V
op
VDD
LCD segments
BP0
state 1
state 2
BP1
BP2
Sn
Sn
+
1
Sn
+
2
At any instant (t):
Vstate 1(t) = VS (t)
−
VBP0(t)
n
Vop
√33
= 0.638Vop
Von(rms) =
9
Vstate 2(t) = VSn(t)
−
VBP1(t)
V
Voff(rms) = op = 0.333Vop
3
(b) resultant waveforms
at LCD segment
MGG395
Fig.7 Waveforms for 1 : 3 multiplex drive mode: V
op
= V
DD
−
V
LCD
.
1998 May 04
11
PHILIPS [ NXP SEMICONDUCTORS ]
