Philips Semiconductors
Product specification
Universal LCD driver for low multiplex
rates
PCF8576
T
frame
V
DD
LCD segments
(V
DD
V
V
)/2
)/2
BP0
LCD
LCD
V
LCD
DD
state 1
V
state 2
BP1 (V
V
DD
LCD
DD
V
S
n
V
V
LCD
DD
S
n
1
V
V
LCD
(a) waveforms at driver
op
V
/2
/2
op
0
state 1
V
V
op
op
V
op
V
/2
/2
op
0
state 2
V
V
op
op
(b) resultant waveforms
at LCD segment
MBE540
Vstate1(t) = VS (t) – VBP0(t)
n
Von(rms) = 0.791Vop
Vstate2(t) = VS (t) – VBP1(t)
n
Voff(rms) = 0.354Vop
Fig.5 Waveforms for the 1 : 2 multiplex drive mode with 1⁄2bias (Vop = VDD − VLCD).
1998 Feb 06
10