1.

General description

The PCA9507 is a 2-wire serial bus extender providing 3.3 V to 5 V level shift that allows

the data (SDA) and the clock (SCL) line as well as the rise time accelerator on port A

enabling the bus to drive a load up to 1400 pF or distance of 18 m on port A, and 400 pF

on port B. Using the PCA9507 enables the system designer to isolate bus capacitance to

meet HDMI DDC version 1.3 distance specification. The SDA and SCL pins are

overvoltage tolerant and are high-impedance when the PCA9507 is unpowered.

The port B drivers with static level offset behave much like the drivers on the PCA9515

device, while the port A drivers integrate the rise time accelerator, sink more current and

eliminate the static offset voltage. This results in a LOW on port B translating into a nearly

0 V LOW on port A. The static level offset design of the port B I/O drivers prevent them

from being connected to another device that has rise time accelerator including the

PCA9510, PCA9511, PCA9512, PCA9513, PCA9514, PCA9515, PCA9516A, PCA9517

(B-side), or PCA9518. The port A sides of two or more PCA9507s can be connected

together, however, to allow a star topography with port A on the common bus, and port A

can be connected directly to any other buffer with static or dynamic offset voltage. Multiple

PCA9507s can be connected in series, port A to port B, with no build-up in offset voltage

with only time of flight delays to consider. Rise time accelerator on port A is turned on

pin can also be used to turn the drivers on and off under system control. Caution should

be observed to only change the state of the enable pin when the bus is idle. The output

pull-down on the port B internal buffer LOW is set for approximately 0.5 V, while the input

threshold of the internal buffer is set about 70 mV lower (0.43 V). When the port B I/O is

driven LOW internally, the LOW is not recognized as a LOW by the input. This prevents a

lock-up condition from occurring.

2.

Features

400 pF on port B

PCA9507

Rev. 01 — 7 February 2008

Product data sheet