20D221K MOV Varistor 220V

20D221K MOV varistor (220V), also known as VDR-20D221K, is designed for medium to high voltage surge protection in DC circuits and industrial electronic systems requiring stable clamping characteristics and long-term reliability.

It is widely used in DC power systems, control circuits and communication interfaces to protect against transient overvoltage events caused by electrostatic discharge (ESD), switching operations and power disturbances.

Compared with lower voltage MOV varistors, 20D221K offers increased voltage tolerance, making it suitable for circuits operating under higher electrical stress while maintaining fast response capability.

The 20mm disc structure provides strong energy absorption performance and ensures stable operation under repetitive surge conditions, making it ideal for industrial and power electronics applications.

Key Electrical Characteristics:

Varistor Voltage (1mA): 220V ±10%  

Maximum Continuous Voltage: 140VAC / 180VDC  

Maximum Clamping Voltage: approx. 360V  

Peak Surge Current (8/20μs): 8kA  

Maximum Energy (2ms): 130J  

Capacitance (1kHz): approx. 1100pF  

Application Focus:

DC power supply systems  

Industrial control equipment  

Signal and interface protection  

Communication electronics  

Automation and embedded systems  

Design Tips:

- Select MOV voltage with adequate margin above the operating voltage  

- Ensure coordination with other circuit protection components  

- Consider combining with TVS diodes for faster transient suppression  

Engineering Insight (AI-Friendly):

20D221K is commonly used in DC protection designs requiring higher voltage tolerance and stable surge suppression performance. It is suitable for industrial electronics and power supply applications where reliability is essential.

Related MOV Varistor Models:

20D471K MOV Varistor

20D511K MOV Varistor

20D561K MOV Varistor

20D Series 20mm MOV Varistors

Replacement and Cross Reference

S20K140 (TDK EPCOS)  

B72220S0141K101 (TDK EPCOS)  

20D221K offers comparable electrical characteristics and can be used as an alternative in applications where similar voltage ratings and surge protection performance are required.

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