TVS - Diodes

Transient Voltage Suppression (TVS) Diodes are semiconductor components designed to protect delicate electronics from overvoltage caused by electrostatic discharge (ESD) and inductive load switching. The SMCJ20CATR is a unidirectional diode commonly used in these applications.

SMCJ20CATR Application Field

The SMCJ20CATR is used to protect sensitive electronic components against ESD and other transient overvoltage. It is very important to select the right TVS for a given application. Below are the criteria typically used to define the characteristics of a transient voltage suppression device:

• Standoff Voltage: Represents the voltage at which the diode is turned off and begins to begin its clamping action.
• Clamping Voltage: The peak clamping voltage of the diode. The typical voltage rating is 5V for this type of diode.
• Maximum ESD: Maximum electrostatic discharge (ESD) rating for the diode. This is a safety characteristic that prevents the device from being overstressed. The maximum ESD rating for the SMCJ20CATR is 8500V.

The SMCJ20CATR is typically used in applications requiring fast response time and low capacitance. It is well-suited for protection circuits for telecommunications, consumer electronics, and television.

SMCJ20CATR Working Principle

The SMCJ20CATR is a type of unidirectional TVS diode. It is designed to protect other electronic components against transient overvoltage caused by ESD. It is essentially a diode connected in reverse bias with a PN junction breakdown voltage greater than the operating voltage of the system. At initial normal operation, the diode is reverse biased and does not conduct. When an overvoltage condition arises, the diode is forward biased by the overvoltage and begins to conduct. As a result, the overvoltage is ‘clamped’ and the current is diverted away from the vulnerable electronics.

The smoothing and damping of the voltage spike is achieved by connecting the diode in series with a reverse-biased diode which functions as a capacitor. This additional diode provides additional capacitivitance and reduces the amplitude of the waveform. This method of ‘clamping’ is known as ‘Zener-clamping’.

The main benefits of the SMCJ20CATR are its fast response time, low capacitance, and 8500V maximum ESD rating. This makes it an ideal choice for applications that require fast response time and robust ESD protection.