In recent years, the word “E-bike” or “Electric Assist Bike” has been constantly showing up in different media. Due to the needs for social distancing while outside during the coronavirus pandemic, there has been a rush on bicycle or E-bike shops around the world. E-bikes are becoming one of the most attractive and popular transportation options because of the advantages of energy efficiency, being environmentally friendly, lower cost and no licensing required. E-bikes look almost like regular bikes and both have pedals. E-bikes are considered pedal-assisted bikes, meaning you’ll get an extra kick of motor power to aid the pedaling effort. Unlike regular bikes, E-bikes intelligently provide multiple power levels under different modes or depending on how fast the rider is turning the pedals, enabling consumers to use less effort to climb uphill easily, and for longer riding time and larger trips. They can properly offer some assistance without compromising the joy of cycling.
According to the market researches, there are still many people who do not understand well the substantial differences among an electric assist bike, an electric bike and an electric motorcycle. Based on the power sources and speed limits, they are classified as shown in Table 1. In addition, the electric assist bikes currently available in the market can also be subdivided into electric-assist city bikes, electric-assist road bikes and electric-assist mountain bikes. The major difference is the purpose of use: for recreation, commuting or fitness. Among them, the most popular type, the electric-assist city bikes, can not only be used for daily commutes to work, but also help riders to experience a fun riding with the whole family. However, this kind of products is very susceptible to electrostatic discharge (ESD) generated by human body and affected by electrical over stress (EOS) where has higher energy at the charging power supply. Since E-bikes run in different weather conditions and have higher operating temperatures, it is easy to cause an abnormal condition in the electronic system, resulting in product damage which requires a return to repair, or even severely damaging the brand’s image and consumers’ trust and loyalty.
Regular bikes | Electric assist bikes | Electric bikes |
Electric motorcycles | |
Power sources |
Pedaling power | pedaling power supplemented by electric motor | Battery powered motor |
Battery powered motor |
Speed | X | <25km/hr | <25km/hr | Subject to local speed limits |
Pedal requirements | O | O | X | X |
License requirements | X | X | X | O |
Helmet laws | X | X (but recommended to wear) | O | O |
Table 1. Classification of two wheeled vehicles and their differences
Modern E-bike system often requires more compact modules, smaller size of PCB and more advanced manufacturing process, which makes the product more susceptible and sensitive to electrostatic discharge. Therefore, the ESD testing requirements have become more and more stringent, and output voltage contact discharge at 8 kV of IEC 61000-4-2 is considered a basic standard. This testing method is used to simulate the event of electrical equipment subjected to static electricity discharges when operated by consumers. As long as including an appropriate ESD/EOS protection unit in the static sensitive components, signal wiring and power terminals in the design phase, the preventive actions can be taken in advance to avoid damage to the back-end products or system crash.
Amazing Microelectronic Corp. possess advanced technology of ESD protection design, and have developed a wide range of ESD protection components, especially for the E-bike protection requirements, in various package sizes and specifications that allows the customers to freely choose according to the requirements of each product, as shown in Figure 1. With its own patented technology, the Amazing Microelectronic Corp. has launched a series of electrostatic protection components, and has provided the 0402 or multi-channel array solutions for different applications. As shown in Figure 2, each single ESD protection unit is able to sustain at least 8 kV contact discharge/15 kV air discharge with EOS protection. Among them, the package size of 0402 is only 1.0 mm x 0.6 mm with thickness of 0.5 mm, which can meet the needs of small package for E-bikes. With the future of technology trends, the Amazing Microelectronic Corp. will continue to develop more ESD protection components to meet market and customer demands, and offer the perfect solutions such as customized products to the customers.
Figure 1. Amazing’s solutions for E-bike application
Application | Parts | Package | Cin | ESD(Con/Air) | Surge | |
CAN Bus TVS | AZ4824-02S | SOT23-3L | 38pF | 30kV/30kV | 6.5A | |
Power | 5V | AZ3005-01G | SOD123 | 1300pF |
30kV/30kV | 60A |
Power | 12V | AZ4012-01G | SOD123 | 290pF |
30kV/30kV | 20A |
Power | 24V | AZ4024-01G | SOD123 | 450pF |
30kV/30kV | 25A |
Power | 36V | AZ4045-01G | SOD123 | 240pF |
30kV/30kV | 15A |
LED | AZ5725-01F | DFN1006(0402) | 8pF | 15kV/15kV | N/A | |
Bluetooth | AZ5325-01F | DFN1006(0402) | 0.5pF | 8kV/15kV | N/A | |
GPIO/UART | AZ5413-01F | DFN1006(0402) | 0.75pF | 20kV/20kV | 7.5A | |
Button | AZ5123-01F | DFN1006(0402) | 13.5pF | 16kV/16kV | 5A |
Figure 2. TVS parameters of Amazing’s solutions in E-bike application
Image sources: https://pngtree.com/