U disk is compact, with simple structure,containing the shell, the control chip, NAND FLASH memory chips, PCB circuit board and a small amount of strength component parts.NAND FLASH memory chip, which is the core component of the flash drive, is responsible for storing data, and costs about 70% of the whole .Therefore, the price movement of NAND FLASH memory chips affects the final retail price of USB directly .
U disk component U disk hardware consists of USB interface, the master chip, flash chips, the composition of the crystal oscillator.USB interface has 4 side connection lines and two data lines (5V and ground) . U disk chip The main brands flash chips used in U disks are Samsung , Hynix, SanDisk, Micron , etc.. FLASH chips is divided into SLC and MLC by types.SLC stands for Single-Level Cell, or single-cell flash memory, while the MLC full name is the Multi-Level Cell, namely multi-level cell flash memory.The difference between them lies in that every unit of SLC can only store one data, while each MLC cell can store two data, as to say MCL data density is double the SLC.Due to a single memory cell can only store a Bit of information, the SLC is expensive, but it is of efficiency ,high-speed and high reliability, while the MLC doesn't. The followings are the main difference between them:
1. Theory of life: SLC 10 million times, while MLC 1 million
2. Write speed: SLC is 8MB / S, MLC is 2MB / S
3. Power: energy the SLC consumes is lower than the MLC, about 15% less than the MLC's current consumption under the same conditions.
4. Single Capacity: Because SLC is single-unit storage, the capacity constraints relative to MLC's multi-unit storage areas , the market is also relatively rare for more than 2G single SLC flash memory chips.
Although, compared with SLC, MLC seems to be with many shortcomings, as to a single chip capacity, the current account MLC has absolute advantage.MLC wins SLC in the framework, and manufacturers domestic and foreign have done a lot for the optimization and development on MLC, which is likely to replace the SLC flash memory chips in the future. As with technology advances, nano-process shrinkage, thus speeding up the TLC (Triple-Level Cell), which makes the improvment of NAND flash memory technology much possible, TLC is a production of NAND flash memory structure and a memory storage unit of the structure can store 3element.TLC NAND flash memory technology is the most advanced technology by now .
We set examples with Micro SD cards with 4GB and 8GB of memory capacity, SD 4GB capacity in the flash card is currently in widespread practice with two 16Gb chips to stack. Durning the stacking, the yield will be lower, but if using aTLC chip with 32Gb of capacity to produce 4GB flash card ,it will be more cost-effective in cost structure, and the yield will be improved a lot; as to a capacity of 8GB we can use two 32Gb TLC chips.This has been used TLC NAND flash memory technology allows a much higher capacity Micro SD flash memory, NAND flash memory cost will be greatly reduced.Positive: the chip venders wafer production capacity is of higher grades, higher than 93% of the capacity of the wafer is known as A grade.
Thefilm A has a original packaging and can be provided with quality assurance, so the brand flash memory chip generally use this sort of chip White film: the capacity of the wafer is less than 93% called Downgrade Flash, which no longer be branded with original radium engraved logo, instead of it the process is done by some small package plants.
Sufficiency of which is relatively stable with the general known as white tablets.The price usually is 70 percent to 80 percent of film A. Black chip: the chip package is of a serious shortage of capacity, quality is difficult to guarantee .Another part of the black pieces are made of the bad memory chip coming from the waste recycling, grinding generally made of flash memory chips .
The main plans of U disk master Master plans are: Skymedi engine programs of Jingtai, Phison of Qunlian, USBest program of Liansheng, Silicon Motion SMI program, OTI program, the core state Chipsbank program, Netac Netac program, Yasukuni (s wins) Alcor and iCreate program, Ameco programs of super Kuwait, Crystal oscillator of the U disk Crystal oscillator is a key component, and it is a devices easy to damage , especially when suffering a large vibration perishable, so if your U disk is unable to be used after a falling,that means it is braken.U dish has two patterns of plugin and patches,many famous brands uses patches.
