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ManualsBrandsTEXAS INSTRUMENTS ManualsInterface ICsInterface IC - buffer amplifiers, accelerators I²C hot swap 400 kHz SOIC 8
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StaggeredConnector
R13
10k
R12
10k
R14
10k
I/OPeripheralCardN
EN
SDAIN
SCLIN
TCA4311
V
CC
GND
CARDN_SCL
CARDN_SDA
SDAOUT
SCLOUT
READY
EN
SDAIN
SCLIN
V
CC
GND
SDAOUT
SCLOUT
READY
EN
Card
Enable/Disable
SDAIN
SCLIN
V
CC
GND
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
R6
10k
I/OPeripheralCard1
TCA4311
CARD_SCL
CARD_SDA
R1
10k
V
CC
R2
10k
Backplane
Backplane
Connector
SDA
BD_SEL
SCL
C1
R3
10k
R7
10k
R11
10k
C3
0.01µF
C5
0.01µF
PowerSupply
HotSwap
PowerSupply
HotSwap
Card
Enable/Disable
Card
Enable/Disable
StaggeredConnector
StaggeredConnector
PowerSupply
HotSwap
0.01µF
TCA4311A
www.ti.com
SCPS226A –JANUARY 2011–REVISED JULY 2012
APPLICATION INFORMATION
Live Insertion and Capacitance Buffering Application
Figure 10 through Figure 11 illustrate the usage of the TCA4311A in applications that take advantage of both its
hot swap controlling and capacitance buffering features. In all of these applications, note that if the I/O cards
were plugged directly into the backplane, all of the backplane and card capacitances would add directly together,
making rise- and fall-time requirements difficult to meet. Placing a TCA4311A on the edge of each card,
however, isolates the card capacitance from the backplane. For a given I/O card, the TCA4311A drives the
capacitance of everything on the card and the backplane must drive only the capacitance of the TCA4311A,
which is less than 10 pF.
Figure 10 shows the TCA4311A in a CompactPCI™ configuration. Connect V
CC
and EN to the output of one of
the CompactPCI power supply Hot Swap circuits. Use a pullup resistor to EN for a card side enable/disable.
V
CC
is monitored by a filtered UVLO circuit. With the V
CC
voltage powering up after all other pins have
established connection, the UVLO circuit ensures that the backplane and card data and clock busses are not
connected until the transients associated with live insertion have settled. Owing to their small capacitance, the
SDAIN and SCLIN pins cause minimal disturbance on the backplane busses when they make contact with the
connector.
Figure 10. Inserting Multiple I/O Cards into a Live Backplane Using the TCA4311A in a CompactPCI
System
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Product Folder Link(s): TCA4311A