MB2100-01A-E Single Port Embedded Emulator Debugger SPEED-BOX Operation Guide, Doc. # 002-05542 Rev. *A
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Product Description
1.5.2
USB circuit specifications
The USB circuit specifications are shown in Table 1-7.
Table 1-7. USB circuit specifications
Note: For this product, a bus powered hub is not available.
1.5.3
Power supply isolation specifications
The SPEED-BOX is equipped with an isolator that isolates the power supply systems of the host
computer and user system. The SPEED-BOX can therefore be directly connected to user systems
where there is an electromotive force between the signal ground (SG) and frame ground (FG; also
called earth).
In general, the SG and FG of a PC are shorted together. (The PC chassis is the FG.) Furthermore,
the PC FG is typically connected to the earth of the environment in which the device is installed via
the earth line of a 3-wire AC cable. In this case, if there is an electromotive force between the SG
and FG of the user system and the FG of the user system is connected to this same earth, then if the
SG line of the host computer was connected to the SG line of the user system, a large current would
flow through the SG line and damage the equipment. This product is built with the power supply
system of the host computer side (USB side) separated from the MDI bus side using isolation
technology such that the SG of the host computer is isolated from the SG of the user system within
the SPEED-BOX.
The withstand voltage of the insulation (the tolerable potential difference between the host computer
SG and the user system SG) is AC250V / DC250V for constantly applied voltages.
Figure 1-4 shows the relationship between the SG/FG and the isolation.
Item
Description
Standards compliance
USB 2.0 (certification acquired)
Communication scheme
Hi Speed / Full speed Bulk Transfer
USB communication speed
(theoretical value)
480Mbps (Hi-Speed)
12Mbps (Full-Speed)
Connector type
Mini B (5pin)
Power supply
Bus Powered
