PCA9513A_PCA9514A_1

© Koninklijke Philips Electronics N.V. 2005. All rights reserved.

Product data sheet

Rev. 01 — 11 October 2005

9 of 25

Philips Semiconductors

PCA9513A; PCA9514A

8.9 Hot swapping and capacitance buffering application

Figure 8 through Figure 11 illustrate the usage of the PCA9513A and PCA9514A 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 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 PCA9513A and PCA9514A drive 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.

Fig 6.

Bus requirements for 3.3 V systems

Fig 7.

Bus requirements for 5 V systems

0

400

300

100

200

002aab582

10

20

30

(k

Ω)

0

recommended

pull-up

rise time > 300 ns

0

400

300

100

200

002aab583

10

5

15

20

(k

Ω)

0

recommended

pull-up

rise time > 300 ns