If you are just beginning to study the design of IoT products, you need to improve in many aspects of PCB design. IoT devices integrate mobility, low power consumption, RF communication, mixed signal function and high-speed data transmission function into a small space. Keeping all these factors in mind will help you design correctly in the first place.
PCB industry standard
If you intend to finally bring new equipment to the market, the equipment must meet or exceed many industry standards. These standards specify several operational requirements to ensure the compatibility between the devices built by others. It is essential to be familiar with and work according to industry standards as soon as possible. If you can design the standard equipment now, then you don’t need to redesign it later.
IPC standard is a good starting point, and it will be necessary to refer to these standards frequently in the design process. For example, IEEE, ISO and ANSI also specify the operation standards of PCB. When the industry standard was studied, it seemed difficult to understand. No one can remember all PCB design standards, so it’s important to focus on the standards applicable to equipment.
Internet of Things Applications and Low Power Design
Not all IoT devices can be plugged into wall sockets. If the equipment is designed to be mobile, you should learn about designing the equipment to use as little electricity as possible. Mobile IoT devices may operate in many different modes, including sleep, standby, burst, etc. The best way to save battery power and ensure the reliability of each mode is to turn off unnecessary parts of the equipment when it is not needed.
It’s best to consider the power consumption in PCB, because it happens in different functional blocks on the board. It is best to divide the PCB into functional blocks and allocate a power consumption budget for each block. If you encounter power consumption problems, you can consult the component supplier. They can recommend alternative components with lower power consumption and keep the cost within the budget.
IoT devices will also need a memory module that will consume energy. Selecting the right memory that can meet the functional requirements can keep the power consumption within the budget. Each type of memory has its advantages and disadvantages. For example, if you choose DMA instead of DRAM, you can save power consumption, but increase latency and throughput. As a designer, you need to weigh the advantages and disadvantages of each type of memory.
Keep the equipment in touch with RF design.
Unless you intend to plug the IoT device directly into the Ethernet port, the device will connect to the Internet wirelessly through WiFi. Bluetooth function may also be available, especially if the device is going to interface with the mobile phone. Many other wireless networking protocols are used to send and receive information using RF signals. If you are not familiar with all kinds of wireless fidelity, it is a good way.
Manage the allocation of official radio spectrum, and allocate some frequency bands for different purposes. For example, WiFi signals operate at a frequency of 2.4 GHz, while other RF protocols will operate at different frequencies in the RF spectrum. Industry standards will also specify design constraints to help ensure the normal operation of the design.
The good news is that it is not necessary to design the RF module from scratch. Ready-made wireless modules that have met the industry standards can be purchased from electronic suppliers and easily integrated into the design. These components can be reduced in overall size, while still including all required functions.
Mixed signal design
Many IoT devices, especially mobile phones and devices used in smart homes, will operate with many sensors, which can make the device interact with the world around it. Sensor outputs in IoT devices must be converted into analog signals of digital signals. Once converted into a digital signal, digital data can be encoded and manipulated just like any other digital data set.
As the amount of data being processed by IoT devices is increasing, the processor must move data between components at a higher speed. The layout will need to consider issues such as crosstalk, clock skew, propagation delay, attenuation and impedance matching. Mixing high-speed digital and analog signals also requires that the analog and digital parts of the board be isolated in different parts of the board.
With proper simulation protocol, the accuracy of IC and behavior construction macro modeling can be ensured. Use powerful SPICE emulator to ensure PCB safety.
Simulation, smaller circuit board, higher component density
If you have been asked to comply with the power requirements and mixed-signal protocols, such as packaging all RF modules, logic IC, power management components, microprocessors, wiring, memory, display, charging/USB ports and other electronic components, it feels like Tetris. Every inch of space is precious. If you want to make full use of the equipment, you need to make full use of all the space.
However, it is not necessary to manage each factor separately. With the help of proper SPICE simulation, it will be possible to track the power supply efficiency, design loopholes, analyze impedance and determine the necessary external dimension limits. SPICE library can provide great help for analysis, and it will have easy-to-access component parameter integration and modeling, as well as templates for building custom models from it.
