The S20K420E3K1 is a varistor from EPCOS (TDK), designed to protect electronic equipment against transient overvoltages. These overvoltages can originate from various sources, including lightning strikes, power line disturbances, and electrostatic discharge (ESD). Varistors are voltage-dependent resistors that exhibit a high resistance at normal operating voltages but a drastically reduced resistance when subjected to high-voltage transients, effectively clamping the voltage and diverting the surge current away from sensitive components.

Applications

• Power supplies: Protection against voltage surges and spikes.
• Consumer electronics: Safeguarding TVs, audio equipment, and other appliances from power line disturbances.
• Industrial equipment: Protecting sensitive control circuits and machinery from voltage transients.
• Telecommunications equipment: Ensuring reliable operation of communication systems by mitigating the effects of lightning and other surges.
• LED lighting: Protecting LED drivers from voltage surges, extending the lifespan of LED fixtures.

Features

• High surge current capability: Able to withstand large surge currents without failure.
• Fast response time: Quickly clamps overvoltages to protect sensitive components.
• Wide operating voltage range: Suitable for various applications with different voltage requirements.
• Compact size: Allows for easy integration into electronic circuits.
• RoHS compliant: Meets environmental regulations regarding hazardous substances.

Benefits

• Enhanced equipment reliability: Protects electronic devices from damage caused by overvoltages.
• Reduced downtime: Minimizes equipment failures due to voltage surges, resulting in less downtime and maintenance costs.
• Extended product lifespan: Protects sensitive components from degradation caused by repeated exposure to overvoltages.
• Improved safety: Reduces the risk of electrical hazards associated with voltage surges.
• Cost-effective protection: Provides a simple and inexpensive solution for overvoltage protection.

Technical Specifications

The S20K420E3K1 varistor has a varistor voltage of 420V. The maximum surge current (8/20 µs pulse) is typically around 6.0kA. The clamping voltage at this surge current level is specified in the datasheet. It is crucial to consult the official EPCOS (TDK) datasheet for comprehensive electrical characteristics, mechanical dimensions, and safety certifications. The operating temperature range is also detailed in the datasheet. The case size is typically a 20mm disc.