mc68hc05jb4p Freescale Semiconductor, Inc, mc68hc05jb4p Datasheet - Page 78

• Manufacturer Part Number: mc68hc05jb4p
• Description: Mc68hc705jb4 Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

GENERAL RELEASE SPECIFICATION
10.4.2.2 Low Speed (1.5 Mbs) Driver Characteristics
10.4.3 Receiver Characteristics
with respect to local ground reference without damage.
The rise and fall time of the signals on this cable are greater than 75 ns to keep
RFI emissions under FCC class B limits, and less than 300 ns to limit timing
delays and signaling skews and distortions. The driver reaches the specified static
signal levels with smooth rise and fall times, and minimal reflections and ringing
when driving the cable. This driver is used only on network segments between low
speed devices and the ports to which they are connected.
USB data transmission is done with differential signals. A differential input receiver
is used to accept the USB data signal. A differential 1 on the bus is represented by
D+ being at least 200 mV more positive than D– as seen at the receiver, and a
differential 0 is represented by D– being at least 200 mV more positive than D+ as
seen at the receiver. The signal cross over point must be between 1.3V and 2.0V.
The receiver features an input sensitivity of 200 mV when both differential data
inputs are in the range of 0.8 V to 2.5 V with respect to the local ground reference.
This is called the common mode input voltage range. Proper data reception is also
achieved when the differential data lines are outside the common mode range, as
shown in Figure 10-13. The receiver can tolerate static input voltages between
–0.5V to 3.8 V with respect to its local ground reference without damage. In
addition to the differential receiver, there is a single-ended receiver (schmitt
trigger) for each of the two data lines.
V
V
SE
SE
(max)
(min)
V
SS
Figure 10-12. Low Speed Driver Signal Waveforms
Freescale Semiconductor, Inc.
(1.5 Mb/s)
ONE BIT
For More Information On This Product,
TIME
UNIVERSAL SERIAL BUS MODULE
Go to: www.freescale.com
February 24, 1999
REFLECTIONS AND RINGING
LEVELS WITH MINIMAL
PASS OUTPUT SPEC
SIGNAL PINS
REV