USB2.0 PHY IC
Drive Low
Slope = 1/40.5 Ohm
Iout
(mA)
Test Limit
10.71 * |VOH|
22
0
Slope = 1/49.5 Ohm
1.09V
0.434*VOH
VOH
0
Vout (Volts)
Figure 6.2 Full-Speed Driver VOL/IOL Characteristics for High-speed Capable Transceiver
6.2
High-speed Signaling Eye Patterns
High-speed USB signals are characterized using eye patterns. For measuring the eye patterns 4
points have been defined (see Figure 6.3). The Universal Serial Bus Specification Rev.2.0 defines the
eye patterns in several 'templates'. The two templates that are relevant to the PHY are shown below.
SMSC GT3200, SMSC USB3250
Revision 1.3 (10-05-04)
DATA1S4HEET
SMSC [ SMSC CORPORATION ]
