9EL2 Circuit Protection

TVS - Thyristors

Thyristors (SCRs - Silicon-Controlled Rectifiers, and TRIACs) are a family of semiconductor devices that provides simple and reliable electrical switching, controlling, and protection. A 9EL2 Thyristor is a three terminal, higher current, ultra-low capacitance pluggable Transient Voltage Suppressor (TVS) component with an off-state blocking voltage of 2.6 V and an on-state and forward voltage of 0.6 V maximum.

9EL2 Application Field

The 9EL2 is typically used as a low capacitance, ultra-low voltage option in applications such as signal & data transmission protection, automotive, medical, and industrial manufacturing. In applications such as I/O port protection and over-voltage protection, the 9EL2 offers superior performance in comparison to conventional two terminal surge protectors. The 9EL2 has a high current capability, offering up to 2.6A of continuous current and up to 8A of peak current.

Working Principle

When a voltage greater than the turn-on voltage is applied across the 9EL2, gate current flows from the anode (A) to the gate (G). This causes a conduction path to be formed between the anode and cathode (K). As current flows through the device, the voltage across the 9EL2 begins to decrease and eventually reaches a point where the device is no longer conducting. When the voltage across the 9EL2 is below the turn-off voltage, the conduction path between the anode and the cathode is no longer present and the device stops conducting current. The device is then in its off-state.

When surge protection is required, the 9EL2 can be used with a Flyback Diode connected between the anode and the cathode. In this configuration, the diode will provide a quick path for current to travel in the opposite direction, protecting the device from excessive voltage spikes. This will help to prevent any damage that may occur to the device due to an overvoltage condition.

The 9EL2 provides a simple and effective solution for protecting both equipment and data from transient overvoltages. The device is a low-cost, low-capacitance, high-current, and easily pluggable surge protector, making it the ideal choice for a wide range of applications.