TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
ERZ-V07D101 Panasonic	VARISTOR 100V 1.75KA DISC 7MM	0
ERZ-E14A751S1 Panasonic	VARISTOR DISC 14MM 750V	889
EZJ-Z1V171AA Panasonic	VARISTOR 170V 0603	23650
ERZ-E10A471CS Panasonic	VARISTOR 470V 4.5KA DISC 11.5MM	0
ERZ-VF2M331 Panasonic	VARISTOR 330V 300A 2SMD JLEAD	2135
ERZ-E11A361 Panasonic	VARISTOR 360V 6KA DISC 13MM	824
ERZ-E11A911 Panasonic	VARISTOR 910V 5KA DISC 14MM	0
ERZ-V07D121 Panasonic	VARISTOR 120V 1.75KA DISC 7MM	0
ERZ-V10D121 Panasonic	VARISTOR 120V 3.5KA DISC 10MM	0
ERZ-E11A621 Panasonic	VARISTOR 620V 5KA DISC 14MM	1002
ERZ-C32CK201W Panasonic	VARISTOR 200V 25KA DISC 32MM	161
ERZ-E14A751 Panasonic	VARISTOR 750V 7.5KA DISC 17.5MM	355
EZA-EG2A50AX Panasonic	VARISTOR 0402	96958
ERZ-HF2M220D Panasonic	VARISTOR 22V SMD TYPE	0
ERZ-U26JP192F Panasonic	SINGLETRANSIENT/SURGE ABSORBERS1	2
ERZ-V20R201 Panasonic	VARISTOR 200V 10KA DISC 20MM	1016
EZJ-Z0V180HA Panasonic	VARISTOR 18V 10A 0402	1919
ERZ-E10A751 Panasonic	VARISTOR 750V 4.5KA DISC 12.50MM	1850
ERZ-E14A391S1 Panasonic	VARISTOR DISC 14MM 390V	1810
ERZ-E10A331CS Panasonic	VARISTOR 330V 4.5KA DISC 11.5MM	0

TVS - Varistors, MOVs

1. Overview

Transient Voltage Suppressors (TVS), Varistors, and Metal Oxide Varistors (MOVs) are critical components for protecting electronic circuits from voltage spikes and electrostatic discharge (ESD). These devices clamp excessive voltage to safe levels, preventing damage to sensitive components. TVS diodes are semiconductor-based solutions with fast response times, while Varistors (including MOVs) use nonlinear resistive materials to absorb energy. Their importance spans industries like telecommunications, automotive, and consumer electronics, ensuring reliability in environments exposed to electrical surges.

2. Main Types and Functional Classification

Type	Functional Characteristics	Application Examples
TVS Diodes	Unidirectional/bidirectional clamping, sub-nanosecond response time, low leakage current	Communication interfaces (USB, HDMI), microcontrollers, power supplies
Zinc Oxide Varistors	High energy absorption, voltage-dependent resistance, aging characteristics	Power line protection, industrial motor drives, surge protection strips
MOVs	Specialized varistors with metal oxide ceramics, optimized for AC/DC applications	Appliances, LED lighting, renewable energy systems

3. Structure and Composition

TVS diodes employ a PN junction semiconductor structure with doping profiles optimized for breakdown characteristics. Varistors consist of polycrystalline ceramic materials (typically zinc oxide grains with additives) sandwiched between metal electrodes, encapsulated in epoxy or molded housings. MOVs use similar materials to varistors but with enhanced grain boundary engineering for improved voltage clamping. All devices incorporate termination coatings (e.g., silver, tin) for PCB mounting compatibility.

4. Key Technical Parameters

Parameter	Description	Importance
Clamping Voltage (V_CLAMP)	Voltage level during surge conduction	Determines protection level for downstream components
Response Time	Time to transition from blocking to clamping mode	TVS: 0.5-10 ns; MOVs: 10-50 ns
Energy Absorption (W_ADM)	Maximum surge energy handling capability	Measured in joules (J), critical for industrial applications
Leakage Current	Off-state current at rated voltage	Impacts power efficiency, typically <100 A

5. Application Fields

Key industries include:

Consumer Electronics: Smartphone charging circuits, TV power supplies
Industrial Automation: PLCs, motor drives, sensor interfaces
Automotive: ECU protection, CAN bus interfaces, battery management systems
Renewable Energy: Solar inverters, wind turbine controllers

Case Study: MOVs in smart meters provide 10kA surge protection against grid transients.

6. Leading Manufacturers and Products

Manufacturer	Representative Product	Key Specifications
Littelfuse	SM712-02	12A, 13.3V clamping, bidirectional TVS for RS-485
Bourns	V14450A	14mm MOV, 450VAC, 210J energy rating
STMicroelectronics	TV05C060	0.5W, 6V, ultra-small TVS for IoT devices

7. Selection Guidelines

Key considerations:

Operating voltage vs. clamping voltage margin
Surge current requirements (8/20 s waveform standard)
Package size constraints (SMD vs. through-hole)
Environmental conditions (temperature, humidity)
Lifespan expectations (MOVs degrade with repeated surges)

8. Industry Trends

Emerging trends include:

Miniaturization: Sub-0201 TVS devices for mobile applications
Higher energy density: MOVs with >1000J/cm absorption
Integration: Combined ESD and surge protection solutions
Automotive focus: AEC-Q qualified devices for 48V systems
Green manufacturing: Lead-free and RoHS-compliant materials