- Standard Microsystems Hi-Speed USB Device Specification Sheet

Hi-Speed USB Device PHY with UTMI Interface
Datasheet
SMSC USB3280 19 Revision 1.5 (11-15-07)
DATASHEET
The eye pattern in Figure 6.4 defines the transmit waveform requirements for a hub (measured at TP2
of Figure 6.3) or a device without a captive cable (measured at TP3 of Figure 6.3). The corresponding
signal levels and timings are given in table below. Time is specified as a percentage of the unit interval
(UI), which represents the nominal bit duration for a 480 Mbit/s transmission rate.
Figure 6.4 Eye Pattern for Transmit Waveform and Eye Pattern Definition
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
Differential
-400mV
Differential
400mV
Unit Interval
100%
Level 2
Level 1
Point 1
Point 2
Point 4 Point 3
Point 6 Point 5
0%
0 Volts
Differential