LPC47M140-NC SMSC [SMSC Corporation], LPC47M140-NC Datasheet - Page 180

• Manufacturer Part Number: LPC47M140-NC
• Description: 128 PIN ENGANCED SUPER I/O CONTROLLER WITH AN LPC INTERFACE AND USB HUB
• Manufacturer: SMSC [SMSC Corporation]

SMSC DS – LPC47M14X
TxD+
TxD-
Low-Speed Downstream port load
CL = 200pF to 600pF
Differential
Low-Speed Buffer
Data Lines
Full Speed: 4 to 20ns at C
Note: The output impedance of the buffer with a series resistance
End of Cable
Driver End
Receiver
of Cable
VSS
VSS
(Rs) is 28 Ω to 44 Ω .
Rs
Rs
FIGURE 10 – DATA SIGNAL RISE AND FALL TIME
FIGURE 12 – LOW-SPEED PORT LOADS
10%
C
C
L
L
FIGURE 11 – FULL SPEED LOAD
3.6V
Rise Time
FIGURE 13 – CABLE DELAY
1.5K
TxD+
TxD-
t
R
L
One Way
Full-Speed Buffer
Cable
= 50pF
Delay
(max)
30ns
50% Point of
Initial Swing
90%
Page 180
Cable Delay
Round Trip
80ns (max)
TxD+
TxD-
Low-Speed upstream port load
Rs
Rs
CL = 50pF to 150pF
Low-Speed Buffer
Crossover
Data Line
Point
C
C
L
L
90%
Rs
Rs
Fall Time
C
C
L
L
t
F
15K
15K
VCRS
10%
Rev. 03/19/2001