Smart bracelet PCB design considerations
- Release on:2019-01-28
As a more popular product form in the past two years, the smart bracelet has attracted more and more people's attention. Although it cannot be accepted by all, its production has indeed caused some changes in the electronic product market.
A smart wristband usually consists of a radio frequency circuit unit, a clock circuit unit, a memory circuit unit, a sensor circuit unit, and a master MCU unit, and the circuit PCB is usually concentrated in a small range for single-sided or double-sided patches. The board is mainly 4 or 6 layers.
Since the versatility is concentrated on a small PCB board, we have to pay special attention to the layout and wiring of the bracelet. Now, some considerations are summarized for reference.
First, the partition layout, pay attention to the trace protection.
As can be seen from the PCB board above, the various parts of the smart bracelet (different color box marks) have a good partition: since the smart bracelet is a collection of digital circuit components, as long as the circuit design is done With the matching resistor and capacitor distribution, the circuit module with certain functions can be completed, 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, data communication and information transfer can be completed through the corresponding connection interface.
In the layout of the circuit module, on the one hand, it is necessary to pay attention to the clock circuit and the crystal oscillator circuit to reach the target discipline through the shortest path. On the other hand, when the clock is routed, care should be taken to avoid the data line to prevent the interference from affecting the stability of the system.
When routing, it is necessary to protect the critical traces, such as the clock generation circuit, the crystal oscillator circuit, etc., whether to carry out copper protection, whether to carry out ring protection, etc., generally in the design will be protected, for the crystal part is required to dig copper .
Second, handle the RF circuit. (GOLDEN FINGER BOARD supplier)
The smart bracelet needs to be linked with the mobile phone when it is used. Therefore, the radio frequency part is a key part. In this part of the design, special care must be taken. Nowadays, the smart bracelets on the market are nothing more than wireless data transmission based on Bluetooth, so the focus is on the processing of Bluetooth radios. If the smart bracelet is only used for data transmission without the need to transmit sound and music, then low-power Bluetooth is the best choice. At design time, the shape of the Bluetooth antenna, the antenna layout, the smart bracelet shell material, etc. all affect the intelligence. An important factor in the performance of the bracelet. An excellent RF antenna engineer is particularly important in the smart bracelet PCB design process.