Product data

PCF8534A All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved.
Product data sheet Rev. 6 — 25 July 2011 15 of 52
NXP Semiconductors
PCF8534A
Universal LCD driver for low multiplex rates
7.4.3 1:3 Multiplex drive mode
When three backplanes are provided in the LCD, the 1:3 multiplex drive mode applies, as
shown in Figure 10
.
V
state1
(t) = V
Sn
(t)  V
BP0
(t).
V
on(RMS)
= 0.638V
LCD
.
V
state2
(t) = V
Sn
(t)  V
BP1
(t).
V
off(RMS)
= 0.333V
LCD
.
Fig 10. Waveforms for the 1:3 multiplex drive mode with
1
⁄
3
bias
013aaa210
state 1
BP0
(b) Resultant waveforms
at LCD segment.
LCD segments
state 2
BP1
state 1
state 2
(a) Waveforms at driver.
BP2
Sn
Sn+1
Sn+2
T
fr
V
SS
V
LCD
2V
LCD
/3
V
LCD
/3
V
SS
V
LCD
2V
LCD
/3
V
LCD
/3
V
SS
V
LCD
2V
LCD
/3
V
LCD
/3
V
SS
V
LCD
2V
LCD
/3
V
LCD
/3
V
SS
V
LCD
2V
LCD
/3
V
LCD
/3
0 V
V
LCD
2V
LCD
/3
−2V
LCD
/3
V
LCD
/3
−V
LCD
/3
−V
LCD
0 V
V
LCD
2V
LCD
/3
−2V
LCD
/3
V
LCD
/3
−V
LCD
/3
−V
LCD
V
SS
V
LCD
2V
LCD
/3
V
LCD
/3