Product Application

Lösungen für SPD application of Photovoltaic System

Advancements in electronic engineering materials and process technology have enabled the miniaturization of electronic devices. As a result, more powerful and smaller electronic components are integrated into printed circuit boards, saving overall circuit board space. The shrinking size of printed circuit boards has led to the widespread use of miniaturized electronic devices in applications such as smart cities, renewable energy power systems, and telecommunications devices.

A Photovoltaic power system that includes multiple power electronics, such as a PV combiner box and DC/AC inverter, is often located outside and is susceptible to lightning strikes. Therefore, the power board of these power electronics requires a high level of surge protection. A miniaturized PCB mounting SPD module soldered directly onto the circuit board was developed to provide lightning surge protection in the limited board space, and it can be applied to the AC side of the power board to offer Class II or Class III surge protection.


The PCB mounting SPD usually employs a metal oxide varistor as its surge-protective component. THINKING TVA22 varistor series is highly reliable and offers a variety of structures for different PCB mounting SPD configurations. The PCB mounting SPD is widely used in the photovoltaic system, which may locate in an outdoor environment with fluctuating temperatures and humidity. Therefore, the varistor for PCB mounting SPD must meet higher reliability requirements. The TVA22 varistor series has the withstanding capability of high surge current, moisture, and extremely high and low temperatures. Additionally, it complies with UL 1449 for use in AC and DC systems. In summary, TVA 22 series can help PCB mounting SPD facilitate effective surge protection for photovoltaic power applications in harsh outdoor conditions.

Features of the TVA22 series

  • ● Body size: 22*25mm
  • ● Max. continuous voltage range: 50Vac to 750Vac; 65Vdc to 980Vdc
  • ● Agency approval: UL 1449 for AC and DC applications
  • ● RoHS & halogen-free compliant
  • ● High surge handling capability in a small footprint
  • ● Reliable protection of AC and DC power supply systems
  • ● Various structures for different installation requirements

The TVA22 series comes in various structures that can be adapted to various PCB-mounting SPD designs. Below are two application examples.

The first example shows that the electrode plate of the TVA22-KQBJ varistor is adopted as the outlet of the PCB-mounting SPD.

The second example shows that the electrode plate of the TVA22 varistor can adapt to the thermal disconnect function of SPD. The PCB mounting SPD that uses TVA22-KQMH structure can activate thermal disconnect under abnormal conditions. According to such SPD mechanism, the TVA22-KQMH varistor is designed with a unique low-temperature disconnect point. During thermal overload, the low-temperature disconnect point and thealarm branch are disconnected to protect the circuits.

With more than 40 years experience in protective component industry, THINKING owns advanced manufacturing process, material development, and overall verification. Its profound experience and advanced technology enable it to offer comprehensive service and reliable protective components to assist customers in overall protection design.