Datasheet

PIC18F2450/4450
DS39760D-page 292 © 2008 Microchip Technology Inc.
FIGURE 21-13: USB SIGNAL TIMING
TABLE 21-15: USB LOW-SPEED TIMING REQUIREMENTS
TABLE 21-16: USB FULL-SPEED REQUIREMENTS
VCRS
USB Data Differential Lines
90%
10%
TLR, TFR
TLF, TFF
Param
No.
Symbol Characteristic Min Typ Max Units Conditions
T
LR Transition Rise Time 75 — 300 ns CL = 200 to 600 pF
TLF Transition Fall Time 75 — 300 ns CL = 200 to 600 pF
T
LRFM Rise/Fall Time Matching 80 — 125 %
Param
No.
Symbol Characteristic Min Typ Max Units Conditions
T
FR Transition Rise Time 4 — 20 ns CL = 50 pF
TFF Transition Fall Time 4 — 20 ns CL = 50 pF
TFRFM Rise/Fall Time Matching 90 — 111.1 %