USB (Universal Serial Bus) Tutorial

What is USB?
Universal Serial Bus is a high speed connectivity standard enabling simple plug and play connections to devices such as modems, digital cameras, camcorders, keyboards and mice. The standard is being supported by many leading suppliers of computers and peripherals. An attractive advantage of USB is that the devices are hot pluggable meaning a live connection/disconnection without data loss or interruption. Devices manufactured to the current USB Revision 2.0 specification are backward compatible with version 1.1.

Applications for USB
Initially USB products were used mainly to link computers and their associated peripherals. Today USB is used in nearly every market including communications, entertainment, medical and automotive.

USB Connectors

The USB specification requires a host system to be equipped with an A type jack. The B type jack is typically found on peripheral devices requiring detachable cables. Therefore, detachable USB cables are configured as an A to B male combination which prevents improper bus configurations and topology miswiring.

USB Cable Construction

L-com’s CSMUAA, CSMUAB, CSMUAX and CSUZAB cable series use 20 AWG power conductors.
All CSMUAMB (Mini B) cable series use 28 AWG power conductors.
ECUSB series uses 26 AWG power conductors, WPUSB series uses 24 AWG power conductors.

USB Topology

USB is a serial, bi-directional bus that can be layered in tiers or star shaped with the use of a hub. USB does not require terminators or manual addressing.

USB Tier Topology

USB Star Topology

Technical Data: USB Limitations

Selecting the right USB cable assembly for your application

L-com takes pride in having a large variety of USB cables. The following selection guide is intended to assist you in selecting the right cable for your need.

Cable Series	Connector Types	Photo	Color	Power Lead Wire AWG	Distinguishing Characteristics
CSMUAB	Male Type A - Male Type B		Light Gray	20	Superior electrical performance compared to industry standard cables - 20 AWG power leads provide maximum current/power transfer
CSMUAA	Male Type A - Male Type A		Light Gray	20	Superior electrical performance compared to industry standard cables - 20 AWG power leads provide maximum current/power transfer
ECUSBAB	Male Type A - Male Type B		Gray	26	Industry standard USB cable suitable in most applications and comparable to competitors cables
CSMUAX	Male Type A - Female Type A		Light Gray	20	Extension cable. Superior electrical performance compared to industry standard cables - 20 AWG power leads provide maximum current/power transfer
CSUZAB	Male Type A - Male Type B		Black	20	Low Smoke Zero Halogen (LSZH) jacket and backshell material significantly reduce the amount of toxic and corrosive gases emitted during combustion. 20 AWG power leads provide maximum current/power transfer
CSMUAMB4	Male Type A - Male Mini-Type B 4 Position		Black	28	Typically used with digital cameras, MP3 players and other small portable devices
CSMUAMB5	Male Type A - Male Mini-Type B 5 Position		Black	28	Most common mini USB connector. Used with digital cameras, MP3 players, cell phones and other small portable devices as well as some GPS units
ECF504-XXAAS	Female Type A Panel Mount - Male Type A		Light Gray	20	Efficiently allows USB cables to be passed through a panel or enclosure. Utilizes metalized plastic housing. 20 AWG power leads provide maximum current/power transfer
ECF504-5M	Female Type A Panel Mount - Cut End		Light Gray	20	Efficiently allows USB cables to be passed through a panel or enclosure. Utilizes metalized plastic housing. Cut end allows user to configure their own assembly or hard wire. 20 AWG power leads provide maximum current/power transfer
UPMAA	Female Type A Panel Mount - Male Type A		Light Gray	20	Efficiently allows USB cables to be passed through a panel or enclosure. Utilizes molded PVC housing. 20 AWG power leads provide maximum current/power transfer
UPMA5	Female Type A Panel Mount - 5 Pin Female Header Connector		Gray	26	Efficiently allows USB cables to be passed through a panel or enclosure. Utilizes molded PVC housing. 5 pin connector mates to standard 0.100" centerline headers
CSMUAXMT-2M	Female Type A Mounting - Male Type A		Light Gray	20	Extends USB computer port for easy mounting via screws or double sided foam tape. 20 AWG power leads provide maximum current/power transfer
COILUAB	Latching Male Type A - Male Type B		Black	28	Latching A connector provides secure connection. Retractable polyurethane cord provides longer life and saves space when compared to standard cables
WPUSBAB	Waterproof Male Type A - Male Type B		Black	24	Waterproof A male mates with waterproof A female connectors to protect against dust, moisture and temporary immersion under water. IP67 rated
WPUSBAX	Waterproof Female Type A - Male Type A		Black	24	Waterproof A female is panel mountable. When mated with waterproof A male or capped with WPUSB-CVR, provides protection against dust, moisture, and temporary immersion under water. IP67 rated
WPUSBBA	Waterproof Female Type B - Male Type A		Black	24	Waterproof B female is panel mountable. When mated with waterproof B male or capped with WPUSB-CVR, provides protection against dust, moisture, and temporary immersion under water. IP67 rated
WPUSBBB	Waterproof Male Type B - Male Type B		Black	24	Waterproof B male mates with waterproof B female connectors to protect against dust, moisture and temporary immersion under water. IP67 rated
WPUSBAF	Waterproof Female Type A - Wire Leads		Various	24	Waterproof A female is panel mountable. When mated with waterproof A male or capped with WPUSB-CVR, provides protection against dust, moisture and temporary immersion under water. IP67 rated. Wire leads allows user to configure their own assembly or hard wire
WPUSBBF	Waterproof Female Type B - Wire Leads		Various	24	Waterproof B female is panel mountable. When mated with waterproof B male or capped with WPUSB-CVR, provides protection against dust, moisture and temporary immersion under water. IP67 rated. Wire leads allows user to configure their own assembly or hard wire