USB3280

DS00001898A-page 16

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The eye pattern in Figure 6-5 defines the receiver sensitivity requirements for a hub (signal applied at test point TP2 of

Figure 6-3) or a device without a captive cable (signal applied at test point TP3 of Figure 6-3). The corresponding signal

levels and timings are given in the table below. Timings are given as a percentage of the unit interval (UI), which rep-

resents the nominal bit duration for a 480 Mbit/s transmission rate.

Voltage Level (D+, D-)

Time (% of Unit Interval)

Level 1

525mV in UI following a transition,

475mV in all others

N/A

Level 2

-525mV in UI following a transition,

-475mV in all others

N/A

Point 1

0V

7.5% UI

Point 2

0V

92.5% UI

Point 3

300mV

37.5% UI

Point 4

300mV

62.5% UI

Point 5

-300mV

37.5% UI

Point 6

-300mV

62.5% UI

FIGURE 6-5:

EYE PATTERN FOR RECEIVE WAVEFORM AND EYE PATTERN DEFINITION

Voltage Level (D+, D-)

Time (% of Unit Interval)

Level 1

575mV

N/A

Level 2

-575mV

N/A

Point 1

0V

15% UI

Point 2

0V

85% UI

Point 3

150mV

35% UI

Point 4

150mV

65% UI

Point 5

-150mV

35% UI

Point 6

-150mV

65% UI

Point 1

0%

100%

Point 2

Level 2

Level 1

Point 3

Point 4

Point 5

Point 6

Differential

-400mV

Differential

400mV

Differential

0 Voltｓ