Справочник Пользователя для Samsung S3C2440A
ELECTRICAL DATA
S3C2440A RISC MICROPROCESSOR
27-42
Table 27-18 USB Full Speed Output Buffer Electrical Characteristics
(V
DD
= 1.2 V
±
0.05 V, T
A
= -40 to 85
°
C, V
EXT
= 3.3V
±
0.3V)
Parameter Symbol
Condition
Min
Max
Unit
Driver Characteristics
Transition Time
Rise Time
Fall Time
TR
TF
CL = 50pF
CL = 50pF
4.0
4.0
20
20
ns
Rise/Fall Time Matching
Trfm
(TR / TF )
90
111.1
%
Output Signal Crossover Voltage
Vcrs
1.3
2.0
V
Drive Output Resistance
Zdrv
Steady state drive
28
44
ohm
Table 27-19 USB Low Speed Output Buffer Electrical Characteristics
(V
DD
= 1.2 V
±
0.05 V, T
A
= -40 to 85
°
C, V
EXT
= 3.3V
±
0.3V)
Parameter Symbol
Condition
Min
Max
Unit
Driver Characteristics
75
Rising Time
TR
CL = 50pF
CL = 350pF
300
75
Falling Time
TF
CL = 50pF
CL = 350pF
300
ns
Rise/Fall Time Matching
Trfm
(Tr / Tf )
80
125
%
Output Signal Crossover Voltage
Vcrs
1.3
2.0
V
Note: All measurement conditions are in accordance with the Universal Serial Bus Specification 1.1 Final Draft Revision.