Application information

STHDMI002A

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9

Application information

9.1

Power supply sequencing

Proper power-supply sequencing is advised for all CMOS devices. It is recommended

9.2

Supply bypassing

9.3

Differential traces

The high-speed TMDS inputs are the most critical parts for the device. There are several

considerations to minimize discontinuities on these transmission lines between the connectors

and the device.

a)

Maintain 100-

Ω differential transmission line impedance into and out of the

STHDMI002A.

b)

Keep an uninterrupted ground plane below the high-speed I/Os.

c)

Keep the ground-path vias to the device as close as possible to allow the shortest

return current path.

d)

Layout of the TMDS differential inputs should be with the shortest stubs from the

connectors.

Output trace characteristics affect the performance of the STHDMI002A. Use controlled

impedance traces to match trace impedance to both the transmission medium impedance and

termination resistor. Run the differential traces close together to minimize the effects of the

noise. Reduce skew by matching the electrical length of the traces. Avoid discontinuities in the

differential trace layout. Avoid 90 degree turns and minimize the number of vias to further

prevent impedance discontinuities.