Input/Output Interfaces

5.7.4 USB Cable Data

The recommended cable length between the host and the USB device should be no longer than sixteen feet for full-channel (12 MB/s) operation, depending on cable specification (see following table).

Table 5-23.

USB Cable Length Data

Conductor Size

Resistance

Maximum Length

 

 

 

20 AWG

0.036 Ω

16.4 ft (5.00 m)

 

 

 

22 AWG

0.057 Ω

9.94 ft (3.03 m)

 

 

 

24 AWG

0.091 Ω

6.82 ft (2.08 m)

 

 

 

26 AWG

0.145 Ω

4.30 ft (1.31 m)

 

 

 

28 AWG

0.232 Ω

2.66 ft (0.81 m)

 

 

 

NOTE:

 

 

For sub-channel (1.5 MB/s) operation and/or when using sub-standard cable shorter lengths may be allowable and/or necessary.

The shield, chassis ground, and power ground should be tied together at the host end but left unconnected at the device end to avoid ground loops.

 

Color code

 

 

Signal

Insulation color

 

 

Data +

Green

 

 

Data -

White

 

 

Vcc

Red

 

 

Ground

Black

 

 

Technical Reference Guide

361834-002

5-29