Datasheet

PCA9518_5 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 05 — 2 December 2008 3 of 21
NXP Semiconductors
PCA9518
Expandable 5-channel I
2
C-bus hub
4. Block diagram
A more detailed view of Figure 1 buffer is shown in Figure 2.
The output pull-down voltage of each internal buffer is set for approximately 0.5 V, while
the input threshold of each internal buffer is set about 0.07 V lower, when the output is
internally driven LOW. This prevents a lock-up condition from occurring.
Fig 1. Block diagram of PCA9518
PCA9518
002aae325
EXPSCL1
V
CC
EXPSCL2
EXPSDA2
SCL0
EXPSDA1
SDA0
EN4
SCL1
SDA4
SDA1
SCL4
EN1
EN3
SCL2
SDA3
SDA2
SCL3
GND
BUFFER
BUFFER
BUFFER
HUB
LOGIC
BUFFER
BUFFER
BUFFER
BUFFER
BUFFER
HUB
LOGIC
BUFFER
BUFFER
EN2
Fig 2. Buffer detail
002aac531
to output
in
inc
data
enable