Layout considerations

AN3357

8/10

Doc ID 018580 Rev 1

4

Layout considerations

PCB layout must be optimized to take advantage of all performances of the HSP061-8M16.

For ESD protection efficiency, the HSP061-8M16 must be located as close as possible to

the connector. This will avoid disturbance propagation to other components through the

coupling effect.

To avoid the inductance effect of PCB tracks, it is required to go directly from the connector

to the HSP061-8M16 and then after to go to the HDMI circuit. Vias to connect the ground

pins of HSP061-8M16 to the ground plane must be as many as possible and placed as

close as possible to the protection device to reduce parasitic inductance on the ground

return path. Vias to connect ground plane and the connector can be located on both sides of

the connector.

To be compliant with HDMI requirements, differential pairs must be designed with 100

Ω

differential impedance from the connector to the IC. The length of each line in the same

differential pair must be equal to minimize intra pair skew. Length of lines in different

differential pair must also be as equal as far as possible to minimize inter pair skew. Track

width must be calculated depending on PCB characteristics (relative permittivity, spacing,

number of layers…)

Figure 10 shows an example of PCB layout for HSP061-8M16 with an HDMI type A SMD

connector..

Figure 10.

Layout example for HSP061-8M16 with HDMI type A SMD connector

As short as possible

100

differential pairs

Ω