PCA9510ADP NXP [NXP Semiconductors], PCA9510ADP Datasheet - Page 8

• Manufacturer Part Number: PCA9510ADP
• Description: Hot swappable I2C-bus and SMBus bus buffer
• Manufacturer: NXP [NXP Semiconductors]

NXP Semiconductors
PCA9510A_4
Product data sheet
8.8 Hot swapping and capacitance buffering application
Figure 7
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
PCA9510A 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.
Fig 5.
Fig 6.
(1) Unshaded area indicates recommended pull-up.
(1) Unshaded area indicates recommended pull-up.
R
(k )
R
(k )
PU
PU
through
50
40
30
20
10
Bus requirements for 3.3 V systems
70
60
50
40
30
20
10
Bus requirements for 5 V systems
0
0
0
0
Figure 10
R
max
(1)
(1)
Rev. 04 — 18 August 2009
= 65.7 k
R
max
rise time = 20 ns
rise time = 300 ns
rise time = 1000 ns
rise time = 20 ns
rise time = 300 ns
rise time = 1000 ns
100
100
illustrate the usage of the PCA9510A in applications that take
= 45 k
Hot swappable I
200
200
R
R
min
min
= 1 k
= 1.7 k
2
C-bus and SMBus bus buffer
300
300
PCA9510A
C
C
b
b
(pF)
(pF)
002aae778
002aae779
© NXP B.V. 2009. All rights reserved.
400
400
8 of 24