OVP component prices stabilize, mechanical and electrical performance are key to purchasing

Overvoltage protection There are many kinds of devices to choose from in the design, such as transient suppression diodes ( TVS ), varistors , semiconductor discharge tubes, electrostatic protection devices ( ESD ), ceramic discharge tubes, glass gas discharge tubes, etc., which are applied in different fields according to their different characteristics. For example, the advantage of the TVS solution is its strong clamping ability, which is more suitable for secondary protection, IC/ASIC protection and telecommunication line protection; the varistor solution has fast response time and strong clamping ability, which is more suitable for power line protection, large surge protection and telecommunication line protection; and the outstanding features of the glass discharge tube solution are ultra-low inter-electrode capacitance and high discharge current, which is more suitable for cable TV protection, power module protection and telecommunication infrastructure protection; the ceramic gas discharge tube solution has outstanding performance in fast response time and clamping ability, and is often used for switching power supply protection and xDSL line protection.

Overvoltage protection device International manufacturers mainly include Tyco Electronics Circuit Protection Division, TDK-EPC, Vishay, Maxim, Bourns, Littelfuse. Taiwanese manufacturers such as Junyao Electronics and Jingyan Technology are also very active in this field. The development of mainland manufacturers such as Shanghai Guangyu Ruixin, Deepwave Electronics, and Hefei Yuntong is eye-catching. Although international manufacturers started earlier, Taiwanese and mainland Chinese manufacturers have accumulated certain technology and outstanding cost-effectiveness, winning the support of some major customers.

Ms. Wang Zhijuan, Vice President of Marketing, Greater China, EPCOS, Director of Ceramic Components and Sensors Marketing, Member of TDK-EPC Group

Price trend will remain stable

After the market downturn in 2008-2009, component suppliers had very high profits in 2009-2010. The reason for this change is simple: suppliers cut costs drastically, followed by strong demand, which in turn led to high equipment utilization. This situation has led to severe shortages of some products, including overvoltage protection devices. In this case, the price trend of overvoltage protection devices has become a topic of concern in the industry.

Most manufacturers believe that the price of overvoltage protection devices will remain stable. Ms. Wang Zhijuan, deputy director of the Greater China Marketing Department and director of the Ceramic Components and Sensors Marketing Department of EPCOS, a member of the TDK-EPC Group, expects that even if the price of raw materials tends to rise, the price of OVP will remain stable. Coincident with this view, Guo Tao, an application engineer of the Shanghai Raychem Circuit Protection Department of Tyco Electronics, said that although the market demand for overvoltage protection devices will further increase in the future, its price will remain stable as the supply volume increases accordingly. Xie Cheng, marketing manager of Junyao Electronics, believes that prices may rise steadily. He said: "For the domestic market, the recent price trend of overvoltage protection devices will not decrease. Driven by factors such as global overall inflation, the strong demand for raw materials in the solar energy industry, the continued increase in China's domestic demand, and the recovery of exports of related electronic, power, and communication products, the price of overvoltage protectors may even rise slightly."

There are more and more opportunities in the overvoltage protection market: the demand for miniaturized overvoltage protection devices has increased due to e-books, smart phones, etc.; for the domestic market, the rapid development of industries such as home appliances going to the countryside, smart grids, and solar controllers has gradually expanded the production capacity of related manufacturing industries, and the resulting demand for ordinary lightning protection products has steadily increased. Coupled with the improvement of some domestic industrial standards, multi-level protection solutions have fully penetrated into related terminal products. The circuit protection industry, including overvoltage protection, is expected to achieve structural growth.

It is expected that 2011 and 2012 will be a good period for the rapid development of overvoltage protection devices. Because of another round of construction of telecommunication infrastructure, a large number of thyristors, gas tubes, surge resistors and avalanche diodes will be consumed in the protection of voice and data conversion, base stations and modems in secondary line cards. These demands will once again ignite the market.

Although the market prospects are bright, overvoltage protection is facing the hidden danger of "cutting corners". For example, some domestic companies reduce the necessary components of the first-level protection due to cost considerations, which causes considerable hidden dangers in products, reduces the brand value of customers, or reduces the added value of Made in China. There are also hidden dangers in reducing some necessary protection components in products that require multi-level protection. This is a digression and will not be mentioned for now.

The most important and critical thing to pay attention to during the procurement process is whether the mechanical and electrical performance of the overvoltage protection device meets the design specifications, such as mechanical size, packaging form, operating voltage, operating voltage, current capacity, etc. However, in actual procurement, this key point is often the most easily overlooked part. In addition, the performance stability, reliability, delivery cycle, sales service, and continuous development capabilities of the supplier should also be considered.

Mechanical and electrical performance are key to purchasing

When purchasing overvoltage protection devices, especially for 3C products, the importance of the size of overvoltage protection devices is self-evident as the specifications of the products are getting smaller and smaller. Maxim claims to have launched the smallest OVP solution size in the industry. Its OVP device MAX14529E/MAX14530E integrates USB charging detection and ±15kV ESD protection (human body model) in a 3 mm square size, providing up to 28V fault protection, suitable for cellular phones, media players, PDAs and other space-constrained applications, and the chip starts at $1.40 (1000 pieces, FOB USA).

Tyco Electronics' ESD products can provide PESD products with a capacitance of 0.25pF, with a minimum size of 0402, and SESD products with a package size as small as 0201, with a minimum capacitance of 0.5pF. The TG30 SMD gas discharge tube newly launched by TDK-EPC is a miniature three-electrode overvoltage protection device with a size of only 2.8mm×7.2mm. In addition to the fast response time of 0.2μs, its rated impulse current is as high as 2kA, and it always maintains stable performance.

In terms of electrical performance, various types of overvoltage protection devices have different characteristics and correspond to different application ranges. For example, some people in the industry believe that metal oxide varistors (MOVs) and multilayer varistors (MLVs) are widely used because of their low price and good quality, but their inherent high capacitance determines that their application range can only be limited to low-frequency fields and transient voltage suppression of power supplies. Silicon-based PESD protection devices, including Zener diodes, TVS diodes/arrays, etc., although they have the advantages of low and accurate protection voltage, their parasitic capacitance cannot be ignored and are usually difficult to apply to high-speed data communication interfaces, such as HDMI, IEEE1394, etc., and one may not replace the other in the short term.

However, manufacturers are trying to gain greater competitive advantages by improving the electrical performance of devices, and even entering areas that were previously difficult to enter. For example, in terms of electrostatic protection, in addition to the inherent low-capacitance PESD protection devices, the circuit protection department of Tyco Electronics has also launched SESD protection devices with low capacitance and low operating voltage. They have all passed the internal differential loss, return loss and eye diagram tests, and can be easily applied to HDMI1.4, USB3.0, DisplayPort1.1 and the latest DiiVA interface. Without affecting the integrity of the signal, it effectively protects the customer's device port from ESD damage and complies with the IEEE electrostatic test standard.

Jingyan Technology specializes in the design of ESD protection devices for high-speed signal lines. Its recently launched products have made breakthroughs in capacitance and ESD clamping voltage. For example, the USB3.0-exclusive ESD protection device AZ1065-06F, the NFC (Near Field Contacting) system antenna-exclusive ESD protection device AZ4217-01F, and the RF receiving antenna-exclusive ESD protection device AZ5325-01F. Jiang Xinqin, assistant manager of the company's R&D department, introduced that the capacitance of AZ1065-06F is only 0.3pF, which is the only single-chip ESD protection device on the market that can protect USB3.0 interfaces; the capacitance of AZ4217-01F is 0.5pF and can be used in 17V voltage systems, while the capacitance of AZ5325-01F is also only 0.5pF. Jiang Xinqin further stated: "These three ESD protection devices are the only ones on the market that can simultaneously minimize capacitance and ESD clamping voltage, providing the best protection for the system from ESD interference without affecting high-speed signal transmission."

TDK-EPC varistors are striving to provide higher surge currents in smaller sizes, such as its ThermoFuse varistors (ETFV) that prevent overloads and fires. The ETFV series consists of an AdvanceD series chip varistor connected in series with a thermally coupled fuse and integrated in a package. The thermal fuse enclosed in a special plastic disconnects the power supply to the overheated varistor to prevent flames and smoke. ETFV varistors are designed to absorb maximum surge currents with 8/20 μs pulses of 6 to 20 kA at rated voltages between 130 and 420 V. With a surge current capability of 20 kA and a maximum energy absorption capability of 700 J for 2 milliseconds, applications include home appliances, power supplies, inverters and drives for solar installations, and can also be used for general protection of electrical lines and equipment.