mc68hc908jb16 Freescale Semiconductor, Inc, mc68hc908jb16 Datasheet - Page 180

• Manufacturer Part Number: mc68hc908jb16
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Universal Serial Bus Module (USB)
11.7.2.5 Data Signal Rise and Fall Time
Technical Data
180
For low-speed transmissions, the jitter time for any consecutive
differential data transitions must be within
any set of paired differential data transitions. These jitter numbers
include timing variations due to differential buffer delay, rise/fall time
mismatches, internal clock source jitter, noise and other random effects.
The output rise time and fall time are measured between 10% and 90%
of the signal. Edge transition time for the rising and falling edges of low-
speed signals is 75ns (minimum) into a capacitive load (C
and 300ns (maximum) into a capacitive load of 600pF. The rising and
falling edges should be transitioning (monotonic) smoothly when driving
the cable to avoid excessive EMI.
DIFFERENTIAL
DATA LINES
t
Period
JITTER
Universal Serial Bus Module (USB)
Figure 11-14. Data Signal Rise and Fall Time
+
+
C
C
L
L
DIFFERENTIAL
DATA LINES
CONSECUTIVE
Figure 11-13. Data Jitter
TRANSITIONS
LOW SPEED: 75ns at C
10%
TRANSITIONS
RISE TIME
PAIRED
t
R
±
CROSSOVER
90%
25ns and within
POINTS
L
= 200pF, 300ns at C
MC68HC908JB16
Freescale Semiconductor
90%
FALL TIME
t
F
L
= 600 pF
L
) of 200pF
10%
±
10ns for
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Rev. 1.1