AN10658_15 Datasheet, PDF (1/28 Pages) NXP Semiconductors – Sending I2C-bus signals via long communications cables

AN10658
Sending I²C-bus signals via long communications cables
Rev. 01 — 26 February 2008
Application note
Document information
Info
Content
Keywords
I2C-bus, twisted pair cables, Cat5e, high speed, Fast-mode,
Fast-mode Plus, Fm+, inter-IC, SDA, SCL, P82B96, PCA9600, I2C2005-1
Abstract
Reliable I²C-bus communication at high data rates, and over many meters,
can be achieved using widely available twisted-pair communication cable
(e.g. Category 5e and similar 4-pair cables, as typically used for Ethernet
communications).
The two bidirectional I²C-bus signals, SDA and SCL, are split into four
unidirectional signals using P82B96 or PCA9600. Each signal is then
transmitted over a separate twisted pair within the communication cable and
combined again by another P82B96.
The configuration minimizes cable propagation delays and therefore
maximizes speed because transmission line reflections do not affect the
signal integrity.
Differences in local ground potential between the cable ends of at least 5 V
(of either polarity, or ac peak) will not affect the data integrity.
High levels of ESD immunity can be achieved when required.
I²C-bus maximum clock speed calculator.