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PCA9516A Datasheet, PDF (1/19 Pages) NXP Semiconductors – 5-channel I2C hub | |||
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PCA9516A
5-channel I2C-bus hub
Rev. 03 â 23 April 2009
Product data sheet
1. General description
The PCA9516A is a CMOS integrated circuit intended for application in I2C-bus and
SMBus systems.
While retaining all the operating modes and features of the I2C-bus system, it permits
extension of the I2C-bus by buffering both the data (SDAn) and the clock (SCLn) lines,
thus enabling ï¬ve buses of 400 pF.
The I2C-bus capacitance limit of 400 pF restricts the number of devices and bus length.
Using the PCA9516A enables the system designer to divide the bus into ï¬ve segments off
of a hub where any segment-to-segment transition sees only one repeater delay.
It can also be used to run different buses at 5 V and 3.3 V or 400 kHz and 100 kHz buses
where the 100 kHz bus is isolated when 400 kHz operation of the other bus is required.
Two or more PCA9516As cannot be put in series. The PCA9516A design does not
allow this conï¬guration. Since there is no direction pin, slightly different âlegalâ low voltage
levels are used to avoid lock-up conditions between the input and the output of each
repeater in the hub. A âregular LOWâ applied at the input of a PCA9516A will be
propagated as a âbuffered LOWâ with a slightly higher value on all the enabled outputs.
When this âbuffered LOWâ is applied to another PCA9515A, PCA9516A, or PCA9518A in
series, the second PCA9515A, PCA9516A, or PCA9518A will not recognize it as a
âregular LOWâ and will not propagate it as a âbuffered LOWâ again. The
PCA9510A/9511A/9513A/9514A and PCA9512A cannot be used in series with the
PCA9515A, PCA9516A, or PCA9518A, but can be used in series with themselves since
they use shifting instead of static offsets to avoid lock-up conditions.
2. Features
I 5 channel, bidirectional buffer
I I2C-bus and SMBus compatible
I Active HIGH individual repeater enable input
I Open-drain input/outputs
I Lock-up free operation
I Supports arbitration and clock stretching across the repeater
I Accommodates Standard-mode and Fast-mode I2C-bus devices and multiple masters
I Powered-off high-impedance I2C-bus pins
I Operating supply voltage range of 2.3 V to 3.6 V
I 5.5 V tolerant I2C-bus and enable pins
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