The PCB design is throughout our whole life, smart bracelet, which more and more attention nearly two years as a popular form of products. At the same time, also the electronic products market has been produced some changes by it.
A smart bracelet is usually composed of RF circuit unit, clock circuit unit, memory circuit unit, sensor circuit unit and master MCU unit and so on, and circuit PCB is usually concentrated in a small range, single or double-sided patch, and the circuit board is 4 or 6 layers.
Since so many functions focus on a smaller PCB board, then we should pay special attention to the bracelet layout and wiring , and now summarize some of the notes for reference.
1.PCB design circuit partition layout, pay attention to line protection
From the PCB circuit board above can be seen in various parts of the circuit of smart Bracelet (different color box mark) have a good partition: because the smart bracelet is a digital circuit elements together in circuit design as long as the good resistance and capacitance distribution matching, circuit module can complete some functions, which makes the circuit design more concise and easy to find. Although some sensor circuit units use analog circuit technology for data acquisition, once the module is designed as a module, then through the corresponding connection interface can complete data communication and information transmission.
In the circuit layout, on the one hand need to pay attention to the clock circuit and oscillator circuit through the shortest path to reach the goal of discipline, on the other hand, the clock line must pay attention to avoid the data line, to prevent interference affects the stability of the system.
In the line, the need for the protection of key line, such as clock generation circuit, crystal oscillator circuit etc. are copper protection, whether ring protection, generally in the design of protection, for part of the crystal is to dig copper processing.
2.RF circuit handled in PCB design
The smart Bracelet needs to be linked with the mobile phone when using. Therefore, the radio frequency part is the key part,so we must pay special attention to it in this part of the design. Now the smart bracelet on the market is nothing more than Bluetooth based wireless data transmission, so the focus of Bluetooth RF processing.
If the smart bracelet is just used for data transmission without the need for transmission of voice and music, so low power Bluetooth is the best choice in the design of Bluetooth antenna, antenna shape, layout, smart Bracelet shell materials are the important factors influencing the performance of smart bracelet. In the process of smart Bracelet PCB design, an excellent RF antenna engineer is particularly important.
3.ESD protection design should be done well
Different countries and regions have different standards for different products or products of the same ESD requirements, in order to make the products through the relevant test in the design of ESD protection design, but also for the detection of ESD after the design is completed, to ensure the products meet the electronic detection of the local market.
4.Reserved system upgrade interface
A smart Bracelet whether its functional upgrade is convenient or not has an important significance for users or smart Bracelet fans. If a product in the appropriate time to upgrade the software (may be pre-hardware design to some features and in order to catch up with the market software did not keep up, it may be to repair some of the software BUG), which shows the product is still kept R & D process, which for the user is a good psychological compensation. As for which method to use, need to be determined in the early planning and hardware and software planning.