Guide to Second and Third Generation USB (Universal Serial Bus) devices


Second Generation

Within the Second Generation USB (Universal Serial Bus) devices, there is connectivity with USB 2.0. However, they do not use the full bandwidth of 480 Mbit / s that supports USB 2.0 Specification Hi-Speed due to technical limitations of the NAND based flash memory.

The fastest devices of this generation use a dual channel controller, although, they are still far from the possible transfer rate of a hard disk of the current generation, or the maximum high speed USB performance.

The file transfer speeds vary considerably. The units are typically capable of fast read speeds of up to 30 Mbit / s and write at about half that speed. This is about 20 times faster than USB 1.1 devices, which have a maximum speed of 12 Mbit / s.

Third Generation

The standard USB 3.0 provides greatly improved data transfer rates compared to its predecessor, plus support for USB 2.0 ports. The USB 3.0 standard was announced in late 2008, but consumer devices were not available until early 2010.

The USB 3.0 interface specifies transfer rates up to 5 Gbit / s, compared to 40 Mbit / s for USB 2.0.

Even though USB 3.0 interface allows extremely high data rates transfer from 2011 most USB 3.0 Flash drives do not use all the speed of USB 3.0 interface due to limitations of their memory controllers.

Although some memory channel controllers coming into market solve this problem.

Some of these memories store up to 256 MiB of memory (which is 1024 times the initial design of M-Systems).

There are also devices, which apart from their normal function, have a USB memory as attachment included, as some wireless optical mouse or USB Memory with attachment to recognize other types of memory (microSD, m2, etc..).

In August 2010, Imation announces the launch of the new line of security USB Flash Drive Defender F200, with capacities of 1 GiB, 2 GiB, 4 GiB, 8 MiB, 16 MiB and 32 MiB. These storage units have a biometric sensor based ergonomic hardware that validates fingerprint matching identification before allowing access to information.

Components of USBs (Universal Serial Bus)

Internal components of a typical USB memory

1 USB connector
2 Control Device USB Mass Storage
3 Points Test
4 Flash Memory Circuit
5 Crystal Oscillator
7 Power scriptures safety
8 Space available for a second flash memory chip
Primary Components

The typical parts of a USB memory are:

A male USB connector type A (1): Provides the physical interface with the computer.
USB mass storage controller (2): Implements the USB controller and provides linear homogeneous interface for USB serial block-oriented, while hiding the complexity of orientation blocks, removing blocks and balance of wear.

Additional components

A typical device may also include:

Jumpers and Test Points (3): Used in testing during manufacture of the unit or for loading code into the processor.
LEDs (6): Indicates data transfer between the device and the computer.
Write protect switch (7): Used to protect data write or erase operations.

Clearance (8): There is a space to include a second memory circuit. This allows manufacturers to use the same board for devices of different sizes and cater to market needs.

USB connector cover: Reduces the risk of injury and improves the appearance of the device. Some units do not have a cover but feature a retractable USB connection. Other devices have a rotating cover that never separates from the device and avoids the risk of losing it.

Aid for transmission: In many cases, the cap contains a suitable opening for a chain or necklace, however this design increases the risk of losing the device.

For this reason many others have said opening in the body of the device and not at the top, the disadvantage of this design is that the chain or necklace is attached to the device while connected. Many designs bring the opening in both places.

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