pca9512a NXP Semiconductors, pca9512a Datasheet - Page 8

• Manufacturer Part Number: pca9512a
• Description: Pca9512a Level Shifting Hot Swappable I2c-bus And Smbus Bus Buffer
• Manufacturer: NXP Semiconductors

Philips Semiconductors
PCA9512A_1
Product data sheet
Fig 5. Bus requirements for 3.3 V systems
R
(k )
PU
30
20
10
0
0
8.8 Hot swapping and capacitance buffering application
100
recommended
pull-up
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
PCA9512A 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.
R
max
200
= 24 k
rise time > 300 ns
through
300
C
002aab582
Figure 9
b
(pF)
400
Rev. 01 — 7 October 2005
Level shifting hot swappable I
illustrate the usage of the PCA9512A in applications that take
Fig 6. Bus requirements for 5 V systems
R
(k )
PU
20
15
10
5
0
0
100
2
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
recommended
C-bus and SMBus bus buffer
200
pull-up
R
max
rise time > 300 ns
PCA9512A
= 16 k
300
C
002aab583
b
(pF)
400
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