SMAJ20CA-Q

TVS diodes are a type of overvoltage protection device which guard against the damaging effects of transients, often occurring in power and communication lines. Their application range includes the automotive, defense, industrial, medical and aerospace markets. Among TVS diodes, the SMAJ20CA-Q is particularly well-suited for applications requiring high-quality performance.

Overview of SMAJ20CA-Q

The SMAJ20CA-Q is a 20V TVS diode, as the “20” in the name implies. It is a ‘Surface Mount Array’ package, so it takes up very little space in the circuit. It is offered in both 600W unidirectional and bi-directional ratings, depending on the specific application.

Due to its array package format, an array of these devices can be daisy-chained and used in a single circuit to provide higher-level protection. Such an arrangement also helps prevent cross-talk between circuit elements.

Applications of SMAJ20CA-Q

The SMAJ20CA-Q offers a range of features that make it suitable for a wide range of applications. The protection level is up to 20V, which is adequate for most types of applications, such as micro-electronic and communication systems. Its array form factor and its low capacitance make it an ideal candidate for applications with high-impedance or sensitive electronic nodes, such as computers, medical equipment and factory automation systems.

Its low clamping voltage of 5V can also make it suitable for low voltage systems. As it is a bi-directional device, it can be used in both AC and DC applications, and is particularly useful in applications located near high voltage power lines.

Working Principle of SMAJ20CA-Q

The SMAJ20CA-Q works on the principle of backbiased avalanche breakdown. Whenever the voltage across the diode crosses its breakdown voltage (typically 5 - 7V for this diode), the junction breaks down and produces a large current that clamps the voltage to a safe value. This prevents any further damage to the circuit due to extreme voltages.

The device operates in a bidirectional manner and absorbs transients from both the positive and negative polarities. The current and the energy ratings of this device depend on the size of the array package, which influences the thermal impedance as well as the maximum capacitance.

Conclusion

The SMAJ20CA-Q offers excellent protection against transient events, with its bi-directional protection capability and its low clamping voltage. It is a particularly well-suited device for high-impedance applications and is widely used in computers, medical, defense and industrial applications.