Hi team,
What’s different between AC couple and DC couple of Vterm pin (Pin#57)?
Why does the power pin need AC couple?
Should we need AC couple if we use 1.8V for Vterm?
Many thanks.
Regards, Prescott
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Hi team,
What’s different between AC couple and DC couple of Vterm pin (Pin#57)?
Why does the power pin need AC couple?
Should we need AC couple if we use 1.8V for Vterm?
Many thanks.
Regards, Prescott
Hi team,
Please kindly give some feedback for these questions.
Thanks for the support.
Regards, Prescott
Hello Prescott,
The power pin (Vterm, pin#57) does not need an AC coupling capacitor. If you are using 1.8V VDD for Vterm, these AC coupling capacitors must be placed on the high-speed TMDS data lines for HDMI (IN_CLK +/-, IN_D0+/-, IN_D1+/-, IN_D2+/-). Currently, the applications diagram on pages 56 and 57 illustrate these lines as being DC coupled which means that no capacitor needs to be placed on them but only for 3.3V Vterm.
For the AC coupling capacitor value, this will be listed in the HDMI spec for 1.8V Vterm.
3.3V Vterm does not require AC coupling capacitors per the HDMI spec.
-Sean