Layout considerations

AN3318

8/10

Doc ID 18263 Rev 1

4

Layout considerations

PCB layout must be optimized to take advantage of all performances of the HSP061-4NY8.

For ESD protection efficiency, the HSP061-4NY8 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 HSP061-4NY8 and then after to go to the HDMI circuit. Vias to connect the ground pin

of HSP061-4NY8 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 HSP061-4NY8 with an HDMI type A SMD

connector..

Figure 10.

Layout example for HSP061-4NY8 with HDMI type A SMD connector

HDMI type A connector

100

Ω differential pairs

As short as

possible

Vias to ground

as many as possible to reduce

ground connection inductance

HSP06-4NY8

HSP06-4NY8