"What is TransferJet? I believe most people know little about this word.
In recent years, with the popularity of smart phones, tablets and notebooks, people's demand for effective short-range wireless data transmission is increasing. After continuous market test, wireless technologies such as infrared, Bluetooth and NFC have been proved to be more advantageous in some specific fields, but they are not suitable for big data transmission.
In view of this situation, as early as 2008, Sony cooperated with Panasonic, Hitachi, Samsung and other international well-known manufacturers to form a "TransferJet Consortium" to formulate the TransferJet specification.
TransferJet
In short, TransferJet is a short-range wireless transmission technology standard, which combines the easy-to-use characteristics of NFC and the characteristics of UWB (ultra wide band) high-speed transmission. It mainly follows three guidelines:
Point to point, multi-point topology is not supported
Symmetry, both have receive and send functions, and all devices can start or receive connection requests
Backward compatibility: the protocol should be backward compatible with the existing traditional architecture as much as possible
For example, the use of TransferJet is somewhat similar to NFC technology, which allows two close electronic devices to exchange data point-to-point. However, different from NFC, TransferJet is based on the principle of inductive magnetic field, has faster transmission rate, shorter transmission distance and other characteristics. The specific differences between TransferJet and NFC can be referred to the following table:
TransferJet vs. NFC
Through the comparison between TransferJet and NFC, I believe you have a further understanding of this transmission specification. The question is, are there any products based on this specification on the market? In what form does it exist? This is the protagonist that Aiban will introduce to you today - Toshiba TransferJet USB / microusb adapter.
TransferJet USB / microusb adapter
When I first learned about this package, I was really surprised. I believe many people may have imagined countless products based on this specification after knowing the TransferJet specification, but they never expected to appear as a USB adapter first.
Toshiba TransferJet USB / microusb adapter set
But when you think about it, it's both unexpected and reasonable. As a new transmission mode, TransferJet needs an entry point for people to be familiar with and accept. USB is a high-speed data communication standard widely used in computers and many other devices. Toshiba launched TransferJet The purpose of USB adapter is self-evident. It can be said that it starts from the "grass-roots level" to promote the popularization of TransferJet short-range wireless transmission function.
Toshiba TransferJet USB / micro USB adapter kit includes a TransferJet USB adapter tjm35420ux and a TransferJet microusb adapter tjm35420mu.
Transfejet USB adapter - tjm35420ux
TransferJet microusb adapter - tjm35420mu
I believe many friends know how to use these two shapes. It is very simple. Tjm35420ux is used for PC and tjm35420mu is used for mobile phone or tablet with microusb interface (there is no product for iPhone at present). In addition, there are several points to be explained in use:
No networking required
The TransferJet transfer application needs to be installed on both PC and mobile terminals
The TransferJet USB adapter is equipped with a mode switch (the user manual indicates that this mode is an extended function and cannot be used at present. It is unclear what the specific function is)
Pairing confirmation is required for the first transmission between two devices
The distance between the adapters carried by the two devices when outputting data shall not exceed 3cm
Due to the constraints of many factors, it is sometimes very embarrassing in practical use. The laptop is OK. Especially when you want to transmit big data files through desktop computers and mobile terminals, you need to cooperate with the placement distance between adapters. For example, the scene shown in the following figure will appear (you need to pad things to ensure close distance transmission)
High speed wireless data transmission between PC and mobile phone through TransferJet Technology
However, the actual transmission rate is really very fast. In my experience, about 150MB files can be transmitted in a few seconds. Of course, in addition to the data transmission between the computer and the mobile terminal device, if two TransferJet microusb adapters are used, the data of the two mobile terminals can also be transmitted to each other, sharing photos or videos, etc., which is very convenient (as shown in the figure below), provided that both devices support the USB OTG function.
High speed wireless data transmission between mobile phones
After using Toshiba TransferJet USB / microusb adapter for a period of time, the following points are summarized:
It is really good to realize the high-speed sharing of documents and materials without networking and data line, especially between two mobile terminal devices
It must be said that it is a great pity that there is no TransferJet adapter with iPhone lighting interface
The actual transfer rate between the two devices is also subject to the rate of the USB interface
The maximum transmission capacity of a single file is 4GB
The transmission distance is too short. It is not convenient to operate from the perspective of open big data sharing (but on the other hand, the safety of data transmission is guaranteed)
TransferJet USB / microusb adapter disassembly
I believe most engineers will be very curious about the internal design scheme of TransferJet USB / microusb adapter. After all, in the previous simple use process, we can still find that TransferJet technology is not suitable only for the application of USB adapter. It can be said that it is only a transitional product. How to integrate TransferJet technology into existing terminals, such as Bluetooth The popularity of WiFi should be regarded as the final form.
Therefore, simple use is just an appetizer, and disassembly is today's highlight. The two adapters of Toshiba are designed with plastic materials, and the structure is very simple. It is very easy to complete the disassembly work (due to the fixing of viscose, the disassembly is still a little destructive).
Disassembly drawing of TransferJet USB / microusb adapter
Seeing the PCB boards of the two adapters at first glance gives people a feeling of delicacy and compactness. The passive electronic components of the patch on the PCB board basically adopt the small package size of 0201, which makes the whole PCB area more compact. For small objects such as USB adapters, manufacturers that pay attention to industrial design will basically first consider the design of small packaged components, but this will increase the difficulty and cost in design and manufacturing, and not every manufacturer is willing to bear it. However, for big manufacturers such as Toshiba, this does not seem to be a problem. Let's look at the design of each adapter separately.
Transfejet USB adapter - tjm35420ux
For the TransferJet USB adapter with mode switch, the author is still eager to know what kind of function it will be. However, it is a pity that we still can't see what the mode "will" function is from the disassembled PCB.
Disassembly drawing of transfejet USB adapter
We can divide the whole adapter hardware function into two parts. One part is the design of USB communication interface, and the other part is the wireless communication scheme design of TransferJet.
The USB communication interface adopts a common design scheme. The core controller is stm32f205rg of STMicroelectronics, which is internally integrated with a USB controller. This is a Cortex-M3 microcontroller launched by st in the early stage. The market application is very mature. It is packaged in WLCSP, with a size of only 3.6mm * 3.9mm; The implementation of USB transceiver relies on the usb3317 of SMSC, supports USB2.0 and OTG, and low pin interface (ULPI), which is very suitable for small USB devices. From the selection of devices in the whole design scheme, it is not difficult to find that when the function is realized, the size of electronic component packaging has become the key factor in the whole product design.
TransferJet's wireless communication scheme is based on Toshiba's single-chip wireless transmission IC Tc35420axlg, Toshiba's first wireless communication IC based on TransferJet technology, integrates the functions of TransferJet, i.e. wireless, data signal processing, host interface and storage interface, on one chip by using rf-cmos technology.
Tc35420axlg hardware principle block diagram
Tc35420axlg features:
Wireless and digital signal processing functions are integrated on a single chip
Built in RF switch and LNA (low noise amplifier)
Host interface with very high transmission speed
Support SDIO uhs-i interface
Low power consumption: the structure of power reduction makes the battery leakage less
Independent power supply
Output power range: - 62 DBM to - 35 dBm
Small package: lga81: 4.0 mm × 4.0 mm × 0.75 mm (max.)
The PHY transmission rate of tc35420axlg is 560mbps, while the actual maximum data transmission volume is 375mbps The output power of tc35420axlg is very low, so the communication range is also very close (< 3cm). The security of data exchange is guaranteed. Moreover, unlike the wireless RF technology, the inductive magnetic field coupling working mode of tc35420axlg makes its own data communication free from external wireless RF interference, and can also adjust its own transmission rate according to the quality of the wireless medium, The specific relationship between transmission rate and sensitivity is as follows:
-70.7 dBm at Rate 522 Mbps
-77.2 dBm at Rate 261 Mbps
-84.0 dBm at Rate 65 Mbps
Due to the highly integrated design, the tc35420axlg is easy to use and can be easily integrated into existing terminals. It is suitable for various applications, such as household products, office supplies, mobile phones and automotive appliances.
TransferJet microusb adapter - tjm35420mu
If you look at the TransferJet microusb adapter again, you will find that the scheme is basically the same as that of tjm35420ux (USB adapter), but there is no mode switch on the USB adapter, so I won't repeat the introduction here.
Disassembly drawing of TransferJet microusb adapter
It can be seen from the disassembly that the hardware principle of the two adapters is very simple, mainly a combination of single-chip solution based on Toshiba TransferJet wireless communication technology and USB communication interface scheme. The simple hardware principle block diagram is as follows:
Principle block diagram of TransferJet USB / microusb hardware
After watching the simple use and disassembly of Toshiba TransferJet USB / microusb adapter, do you think it is not as good as expected?
It is true that in my personal experience, TransferJet USB / microusb adapter has some shortcomings, but its advantages are also very clear. It is commendable for its security, high-speed transmission characteristics and free from other wireless RF interference. Moreover, TransferJet technology as a USB adapter product itself is not a very suitable application, I prefer to regard it as the beginning of "throwing bricks to attract jade", and the final product form should be to integrate TransferJet technology into existing terminal products, such as WiFi and Bluetooth. You can imagine that in a few years, with the continuous development and improvement of wireless charging and TransferJet technology, for example, the smartphone in your hand can remove the most aesthetic interface for charging and data transmission. Can there be anything cooler than this?
Of course, we still have a long way to go to achieve this goal. We need a large number of manufacturers who "dare to eat crabs first" to support and improve the TransferJet ecosystem. Toshiba's TransferJet USB / microusb adapter can be said to have successfully taken a small step to let people know We realize that there will be such a short-range communication technology that will change the world in the future, and as beneficiaries, we still have to look forward to it, in case it is realized“
Our other product:
