USB3280

DS00001898A-page 14

 2004 - 2015 Microchip Technology Inc.

6.1

Driver Characteristics of Full-Speed Drivers in High-Speed Capable Transceivers

The USB3280 uses a differential output driver to drive the USB data signal onto the USB cable. FIGURE 6-1: Full-Speed

Driver VOH/IOH Characteristics for High-speed Capable Transceiver on page 14 shows the V/I characteristics for a full-

speed driver which is part of a high-speed capable transceiver. The normalized V/I curve for the driver must fall entirely

inside the shaded region. The V/I region is bounded by the minimum driver impedance above (40.5 Ohm) and the max-

imum driver impedance below (49.5 Ohm). The output voltage must be within 10mV of ground when no current is flowing

in or out of the pin.

FIGURE 6-1:

FULL-SPEED DRIVER VOH/IOH CHARACTERISTICS FOR HIGH-SPEED

CAPABLE TRANSCEIVER

FIGURE 6-2:

FULL-SPEED DRIVER VOL/IOL CHARACTERISTICS FOR HIGH-SPEED

CAPABLE TRANSCEIVER

0

0

Drive High

Test Limit

Slope = 1/49.5 Ohm

Slope = 1/40.5 Ohm

(mA)

0

0

Drive Low

(mA)

22

1.09V

Test Limit

Slope = 1/40.5 Ohm

Slope = 1/49.5 Ohm