In today’s home appliance market, inverter air conditioners have become the top choice for many consumers due to their energy efficiency, quiet operation, and comfort. However, during the operation of inverter air conditioners, external factors such as grid fluctuations and lightning strikes can cause transient overvoltage in the system, potentially damaging the air conditioner's circuitry. To protect the circuits of inverter air conditioners, the Transient Voltage Suppressor (TVS) diode was developed, and the SMF15CA is a widely used TVS diode in these air conditioning systems.

1. Basic Characteristics of SMF15CA

The SMF15CA is a bidirectional transient voltage suppressor diode, which means it can be used in circuits regardless of polarity. Its key specifications are as follows:

Reverse Working Voltage (Vrwm): 15V. This is the maximum reverse voltage the diode can handle during normal operation, ensuring that it does not conduct and prevent unnecessary power loss at normal working voltages.

Slkor Transient Protection Diode SMF15CA product photo

Breakdown Voltage (Min/Max): 16.7V/18.5V. When overvoltage occurs in the circuit, the diode will break down and conduct within this voltage range, clamping the overvoltage to a lower level and protecting subsequent circuitry.

Slkor Transient Protection Diode SMF15CA specification

Reverse Leakage Current (Ir): 8.2μA. This is the leakage current when the diode is in reverse bias. The very small leakage current ensures low power consumption during normal operation.

Parameters of Slkor Transient Protection Diode SMF15CA

Peak Pulse Current (Ipp) @ 10/1000μs: 24.4A. This indicates the maximum peak pulse current the diode can withstand during a 10/1000μs pulse waveform, demonstrating its strong capability to handle transient overcurrent.

Maximum Clamping Voltage: 1V. When the diode breaks down and conducts, it can clamp the overvoltage to this low voltage level, effectively protecting subsequent circuits.

Peak Pulse Power (Ppp) @ 10/1000μs: 200W. This indicates the maximum peak pulse power the diode can handle during a 10/1000μs pulse waveform, further highlighting its excellent ability to withstand transient over-energy.

2. The Working Principle of Inverter Air Conditioners and the Importance of Transient Voltage Suppression

Inverter air conditioners adjust the compressor speed via an inverter to regulate the amount of refrigerant circulating through the system, allowing precise control of indoor temperature. Compared to traditional fixed-frequency air conditioners, inverter models offer higher energy efficiency and more comfortable temperature control. However, sensitive components such as the inverter and control circuits in these air conditioners are highly vulnerable to overvoltage. A sudden overvoltage surge can damage these components and even cause a system-wide failure.

Therefore, it is crucial to incorporate transient voltage suppressor diodes such as the SMF15CA into inverter air conditioners. These diodes can quickly conduct when overvoltage occurs, clamping it to a safe level, thereby effectively protecting sensitive components such as the inverter and control circuits from damage.

3. Applications of SMF15CA in Inverter Air Conditioners

In inverter air conditioners, the SMF15CA is typically installed at critical points such as the power input and inverter output. When transient overvoltage is induced by lightning strikes, switching operations, or other factors in the grid, the SMF15CA diode responds rapidly, clamping the overvoltage within a safe range to protect downstream circuits.

Additionally, the SMF15CA offers advantages such as fast response time, compact size, and low power consumption, making it ideal for use in home appliances like inverter air conditioners. Its incorporation not only enhances the reliability of the air conditioning system but also extends its lifespan.

4. Conclusion

With advancements in technology and growing consumer demands for high-performance home appliances, inverter air conditioners have become the mainstream product in the market. The transient voltage suppressor diode SMF15CA plays a vital role as an essential protective component in these systems. Its performance directly impacts the reliability and lifespan of the air conditioner. Therefore, when selecting and using transient voltage suppressor diodes, it is important to consider factors such as polarity, reverse working voltage, breakdown voltage, reverse leakage current, peak pulse current, maximum clamping voltage, and peak pulse power to ensure that it meets the protection needs of inverter air conditioners.

About Slkor：

Slkor has research and development offices in Busan, South Korea, Beijing, China, and Suzhou, China. Most of the wafer manufacturing and packaging and testing are carried out within China. The company employs and collaborates with individuals and organizations worldwide, with a laboratory for product performance and reliability testing and a central warehouse located at its headquarters in Shenzhen. Slkor has filed for over a hundred invention patents, offers more than 2,000 product models, and serves over ten thousand customers globally. Its products are exported to countries and regions including Europe, the Americas, Southeast Asia, and the Middle East, making it one of the rapidly growing semiconductor companies in recent years. With well-established management systems and streamlined workflows, Slkor has rapidly enhanced the brand awareness and reputation of its "SLKOR" brand through its outstanding quality and standardized services. Its product range includes three major series: diodes, transistors, and power devices, with recent introductions of new products such as Hall elements and analog devices, expanding its presence in sensors, Risc-v microcontrollers, and other product categories.