mc68hc908jb8 Freescale Semiconductor, Inc, mc68hc908jb8 Datasheet - Page 133

• Manufacturer Part Number: mc68hc908jb8
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

9.7 Hardware Description
9.7.1 Voltage Regulator
9.7.2 USB Transceiver
MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3
Freescale Semiconductor
The USB module as previously shown in
functional blocks: the low-speed USB transceiver, the USB control logic,
and the USB registers. The following details the function of the regulator,
transceiver, and control logic. See
register settings.
The USB data lines are required by the USB specification to have an
output voltage between 2.8V and 3.6V. The data lines also are required
to have an external 1.5k pull-up resistor connected between a data line
and a voltage source between 3.0V and 3.6V.
worst case electrical connection for the voltage regulator.
The USB transceiver provides the physical interface to the USB D+ and
D– data lines. The transceiver is composed of two parts: an output drive
circuit and a receiver.
TRANSCEIVER
REGULATOR
LOW-SPEED
4.0V – 5.5V
Universal Serial Bus Module (USB)
3.3V
Figure 9-10. Regulator Electrical Connections
D+
D–
R1
USB DATA LINES
R1 = 1.5k
R2 = 15k
9.8 I/O Registers
USB CABLE
Figure 9-2
5%
5%
Universal Serial Bus Module (USB)
Figure 9-10
R2
contains three
for details of
Hardware Description
R2
Technical Data
shows the
HOST
HUB
OR
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