Circuit Protection Device: Reaction Speed ​​Is Key

Current portable devices are increasingly adopting new high-speed serial interface standards, and high-speed interface chips can easily fail due to the destruction of ESD.

At the same time, these interfaces operate at data transmission speeds of up to 500 Mbps. Due to signal integrity requirements, they cannot withstand the large capacitances used in traditional ESD protection methods. Therefore, new ESD protection schemes are needed to ensure high signal integrity. To meet its demand for ESD protection, California Micro Devices, a provider of circuit protection solutions, demonstrated a variety of ESD protection devices at this year's IIC-China.

In the past, electronic manufacturers generally used varistors to achieve circuit protection, but the physical characteristics of such devices would change when subjected to voltage surges, and their service life would be shorter. The circuit protection device of California Microelectronics is based on TVS (Transient Voltage Suppression) technology, which can achieve a smaller volume and a longer service life.

In the face of various circuit protection devices on the market, Huang Yongjia, senior sales manager of the company in China, stated that users should first pay attention to their response speed when choosing. If the system circuit has been affected by the protection of the device, it obviously loses the significance of protection. Secondly, Looking at the protection clamp voltage is usually as low as possible, but also consider the size and package form, especially for small portable applications.

"In fact, the circuit protection device principle is very simple, but the experience is very important in the application, users need professional knowledge to get the best protection," he said.

Circuit protection devices have not yet been widely used. Cost saving is one reason. Some manufacturers do not attach importance to ESD protection of circuits.

Huang Yongjia said: “In the past, equipment interfaces were generally not disconnected after being connected to the line, but now they are different. Interfaces need to be frequently plugged and unplugged, such as USB ports, so that frequent plugging and unplugging can easily lead to ESD hazards. Therefore, the device needs ESD protection. Higher, so we have introduced a series of products specifically for protection of interfaces such as USB, HDMI, etc., which are mainly used in consumer electronic devices."