Datasheet

PCA9511A_4 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 04 — 19 August 2009 9 of 24
NXP Semiconductors
PCA9511A
Hot swappable I
2
C-bus and SMBus bus buffer
8.9 Hot swapping and capacitance buffering application
Figure 7 through Figure 10 illustrate the usage of the PCA9511A in applications that take
advantage of both its hot swapping 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 time and
fall time requirements difficult to meet. Placing a bus buffer on the edge of each card,
however, isolates the card capacitance from the backplane. For a given I/O card, the
PCA9511A drives the capacitance of everything on the card and the backplane must drive
only the capacitance of the bus buffer, which is less than 10 pF, the connector, trace, and
all additional cards on the backplane.
See Application Note AN10160, ‘Hot Swap Bus Buffer’ for more information on
applications and technical assistance.
Remark: The PCA9511A can be used in any combination depending on the number of rise time accelerators that are needed
by the system. Normally only one PCA9511A would be required per bus.
Fig 7. Hot swapping multiple I/O cards into a backplane using the PCA9511A in a cPCI, VME, and AdvancedTCA
system
002aab584
R4
10 kΩ
C1
0.01 µF
SDAOUT
SCLOUT
READY
V
CC
GND
R5
10 kΩ
R6
10 kΩ
R3
10 kΩ
ENABLE
SDAIN
SCLIN
POWER SUPPLY
HOT SWAP
CARD1_SDA
CARD1_SCL
STAGGERED CONNECTOR
I/O PERIPHERAL CARD 1
BACKPLANE
CONNECTOR
R8
10 kΩ
C3
0.01 µF
SDAOUT
SCLOUT
READY
V
CC
GND
R9
10 kΩ
R10
10 kΩ
R7
10 kΩ
ENABLE
SDAIN
SCLIN
POWER SUPPLY
HOT SWAP
CARD2_SDA
CARD2_SCL
STAGGERED CONNECTOR
I/O PERIPHERAL CARD 2
R12
10 kΩ
C5
0.01 µF
SDAOUT
SCLOUT
READY
V
CC
GND
R13
10 kΩ
R14
10 kΩ
R11
10 kΩ
ENABLE
SDAIN
SCLIN
POWER SUPPLY
HOT SWAP
CARDN_SDA
CARDN_SCL
STAGGERED CONNECTOR
I/O PERIPHERAL CARD N
R2
10 kΩ
R1
10 kΩ
V
CC
BACKPLANE
BD_SEL
SDA
SCL