1.

General description

SMBus systems.

enabling virtually an unlimited number of buses of 400 pF.

Using the PCA9518 enables the system designer to divide the bus into an unlimited

number of segments off of a hub where any segment to segment transition sees only one

repeater delay and is multiple master capable on each segment.

using the expansion pins.

The PCA9518 is a wider voltage range (2.3 V to 3.6 V) version of the PCA9518 and also

A PCA9518 cluster cannot be put in series with a PCA9515/16 or with another

PCA9518 cluster. Multiple PCA9518 devices can be grouped with other PCA9518

be sent/received from/to one PCA9518 to/from another PCA9518 within the cluster. Since

there is no direction pin, slightly different ‘legal’ low voltage levels are used to avoid

lock-up conditions between the input and the output of individual repeaters in the cluster.

A ‘regular LOW’ applied at the input of any of the PCA9518 devices will then be

propagated as a ‘buffered LOW’ with a slightly higher value to all enabled outputs in the

PCA9518 cluster. When this ‘buffered LOW’ is applied to a PCA9515 and PCA9516 or

separate PCA9518 cluster (not connected via the EXPxxxn pins) in series, the second

PCA9515 and PCA9516 or PCA9518 cluster will not recognize it as a ‘regular LOW’ and

will not propagate it as a ‘buffered LOW’ again. The PCA9510/9511/9513/9514 and

PCA9512 cannot be used in series with the PCA9515 and PCA9516 or PCA9518, but can

be used in series with themselves since they use shifting instead of static offsets to avoid

lock-up conditions.

PCA9518

Rev. 05 — 2 December 2008

Product data sheet

1.

Only four ports per device are available if individual Enable is required.