AN4138

Characteristics related to HDMI 1.4

Doc ID 023404 Rev 1

3/9

2

Characteristics related to HDMI 1.4

Protection bandwidth must be large enough to be transparent when a high bit rate is

transferred on the line. The equation below give the relationship between lines, pixels, color

depth and bit rate per channel:

HDMI standard give a minimum rise time of 75 ps between 20% and 80%. Considering a

constant slope, this is equal to 100 ps between 10% and 90%.

In order to be transparent, the ESD protection must have a bandwidth in accordance with a

rise time of 100 ps.

Usually, the relations between bandwidth and rise time is defined by the following formula:

tr = 100 ps gives a BW = 3.2 GHz.

Figure 5 shows the cut-off frequency of the HSP061-2N4 is 6 GHz which is high enough to

correctly manage HDMI signals.

Figure 5.

S21 attenuation measurement

Table 1.

Sample characteristics

CEA video

code

Video format

Horizontal

total pixel

per line

Vertical

total lines

per frame

Frame

rate (Hz)

Color

depth

(bits)

HDMI

data rate

(Gbps)

Lane

data rate

(Gbps)

16

1920 x 1080p

2200

1125

60

24

4.46

1.49

30

5.57

1.86

36

6.68

2.23

48

8.91

2.97

Lane data rate = (H_total_pixels) × (V_total_lines) ×

⎛⎞

Color_depth

⎜

⎜

⎝

⎠

3

× (Frame_rate) ×

10

8

BW = 1 / (PI × tr)

300k

1M

3M

10M

30M

100M 300M

1G

3G

-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

IO1

IO2

S21 (dB)

F (Hz)