Datasheet

APPLICATIONINFORMATION
ADDR
P7
P6
P5
P3
P2
P1
P4
GND
INT
SDA
SCL
TCA6408A
SDA
SCL
INT
GND
Keypad
A
B
ENABLE
Master
Controller
5
6
7
9
10
11
12
14
15
13
2
8
16
1
RESET
3
RESET
V
(1.8V)
CCI
V
CC
V
CCP
10k
( 4)
W
´
P0
ALARM
Subsystem1
(e.g., Alarm)
(seeNoteD)
4
100k ( 3)W ´
V
CCP
V
CCI
V
CCI
TCA6408A
SCPS192C–APRIL2009–REVISEDJULY2009............................................................................................................................................................. www.ti.com
Figure14showsanapplicationinwhichtheTCA6408Acanbeused.
A.Deviceaddressconfiguredas0100000forthisexample.
B.P0andP2–P4areconfiguredasinputs.
C.P1andP5–P7areconfiguredasoutputs.
D.Resistorsarerequiredforinputs(onPport)thatmayfloat.Ifadrivertoaninputwillneverlettheinputfloat,aresistor
isnotneeded.Outputs(inthePport)donotneedpullupresistors.
Figure14.TypicalApplication
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