HDMI2C1-6C1 Datasheet, PDF (9/23 Pages) STMicroelectronics – ESD protection and signal booster for HDMI source control stage interface

HDMI2C1-6C1
Application information
Figure 8. Simplified view of the electrical parameters of the HPD block
Signal on HPD link
5V
V_{IH_HPD}
V_{IL_HPD}
HPD_IC signal
2.3.2
HEAC link
The HEAC link is described in the HDMI 1.4 standards as the HDMI ethernet and audio
return channel. It corresponds physically to one differential wired pair made of the Utility line
and the HPD line. Two signals are transmitted through this link.
The first signal corresponds to the HDMI ethernet channel (HEC). The signal is transmitted
in differential mode (bidirectional) through the HEAC link. It is specified by the 100Base-TX
IEEE 802.3 standard (fast ethernet 100Mbps over twisted pair). Therefore, the HEC
integrates an ethernet link into the video cable, enabling IP-based applications over the
HDMI cable.
The second signal corresponds to the audio return channel (ARC). The signal is transmitted
either in common mode (unidirectional, from sink to source) through the HEAC link. It is
specified by the IEC 60958-1 standard. The ARC function integrates an upstream audio
capability, simplifying the cabling of the audiovisual equipment. It is no more necessary to
use a coaxial cable from TV to audio amplifier.
The HDMI2C1-6C1 helps the designer to implement this high added value HEAC function in
the application, protecting the link against the ESD with no disturbance of the signal. It
provides 2 distinct outputs HEAC+ and HEAC in order to ease as much as possible the PCB
layout.
2.4
+5V protection and fault line
The +5 V power supply that the source device has to provide to the HDMI cable is described
by the HDMI 1.4 standard. It must be protected against accidental short circuit that could
occur on the cable side.
The HDMI2C1-6C1 device embeds a low drop current limiter. If an overcurrent is detected,
the HDMI2C1-6C1 limits the current through the +5V power supply. If the current is too high
(short circuit), the device opens the +5V.
Furthermore, the HDMI2C1-6C1 device embeds also an over temperature protection (OTP).
If the internal temperature of the device is reaching a too high value, the +5V supply is
opened in order to protect the application.
DocID025281 Rev 1
9/23
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