Philips Semiconductors
Universal LCD driver for low multiplex rates
Product specification
PCF8576
BP0
BP1
Sn
Sn 1
state 1
state 2
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
Vop
2Vop /3
Vop /3
0
Vop /3
2Vop /3
Vop
Vop
2Vop /3
Vop /3
0
Vop /3
2Vop /3
Vop
T frame
LCD segments
state 1
state 2
(a) waveforms at driver
(b) resultant waveforms
at LCD segment
MBE541
Vstate1(t) = VSn(t) – VBP0(t)
Von(rms) = 0.745Vop
Vstate2(t) = VSn(t) – VBP1(t)
Voff(rms) = 0.333Vop
Fig.6 Waveforms for the 1 : 2 multiplex drive mode with 1⁄3bias (Vop = VDD − VLCD).
2001 Oct 02
11