Datasheet

R3
100k
EN
SDAIN
SCLIN
V
GND
CC
SDAOUT
SCLOUT
READY
EN
SDAIN
SCLIN
V
GND
CC
SDAOUT
SCLOUT
READY
R9
10k
R8
10k
R10
10k
I/OPeripheralCard2
TCA4311
CARD2_SCL
CARD2_SDA
R5
10k
R4
10k
I/OPeriperalCard1
TCA4311
C20.1 Fµ
R7
100k
C40.1 Fµ
CARD_SCL
CARD_SDA
R1
10k
V
CC
R2
10k
Backplane
Backplane
Connector
SDA
SCL
C1
0.01 Fµ
C3
0.01
Fµ
R6
10k
•
•
•
TCA4311A
SCPS226A –JANUARY 2011–REVISED JULY 2012 www.ti.com
Figure 11 shows the TCA4311A in a PCI application, where all of the pins have the same length. In this case,
connect an RC series circuit on the I/O card between V
CC
and EN. An RC product of 10 ms provides a filter to
prevent the TCA4311A from becoming activated until the transients associated with live insertion have settled.
Figure 11. Inserting Multiple I/O Cards into a Live Backplane Using the TCA4311A in a PCI System
Repeater/Bus Extender Application
Users who wish to connect two 2-wire systems separated by a distance can do so by connecting two TCA4311A
back-to-back, as shown in Figure 12. The I
2
C specification allows for 400 pF maximum bus capacitance,
severely limiting the length of the bus. The SMBus specification places no restriction on bus capacitance, but the
limited impedances of devices connected to the bus require systems to remain small if rise- and fall-time
specifications are to be met. The strong pullup and pulldown impedances of the TCA4311A are capable of
meeting rise- and fall-time specifications for one nanofarad of capacitance, thus allowing much more interconnect
distance. In this situation, the differential ground voltage between the two systems may limit the allowed distance,
because a valid logic low voltage with respect to the ground at one end of the system may violate the allowed
V
OL
specification with respect to the ground at the other end. In addition, the connection circuitry offset voltages
of the back-to-back TCA4311A add together, directly contributing to the same problem.
14 Submit Documentation Feedback Copyright © 2011–2012, Texas Instruments Incorporated
Product Folder Link(s): TCA4311A