TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
V05P25P Wickmann / Littelfuse	VARISTOR 39V 500A DISC 5MM	0
FBMOV230M Wickmann / Littelfuse	VARISTOR 360V 40KA AXIAL CYLINDR	0
V07P42AUTO Wickmann / Littelfuse	VARISTOR 68V 800A DISC 7MM	0
V20H320AUTO Wickmann / Littelfuse	VARISTOR 510V 10KA DISC 20MM	0
V320LS7P Wickmann / Littelfuse	VARISTOR 510V 1.2KA DISC 7MM	0
V14H150P Wickmann / Littelfuse	VARISTOR 240V 6.5KA DISC 14MM	0
V575LC80CPX2855 Wickmann / Littelfuse	VARISTOR 910V 10KA DISC 20MM	0
V660LC50AP Wickmann / Littelfuse	VARISTOR 1.08KV 4.5KA DISC 14MM	0
V07E230PL2T Wickmann / Littelfuse	VARISTOR 360V 1.75KA DISC 7MM	0
V26MLA1210NH Wickmann / Littelfuse	VARISTOR 34V 300A 1210	1527
V120ZA4P Wickmann / Littelfuse	VARISTOR 120V 2.5KA DISC 10MM	0
V68MLA1206H Wickmann / Littelfuse	VARISTOR 83V 180A 1206	689
V460LT40CP Wickmann / Littelfuse	VARISTOR 715V 10KA DISC 20MM	0
V60MLA1210H Wickmann / Littelfuse	VARISTOR 75V 250A 1210	0
V120ZS05P Wickmann / Littelfuse	VARISTOR 120V 400A DISC 5MM	0
V460LT40CPX2855 Wickmann / Littelfuse	VARISTOR 715V 10KA DISC 20MM	0
V140LA10AP Wickmann / Littelfuse	VARISTOR 220V 4.5KA DISC 14MM	4483
V661DB40 Wickmann / Littelfuse	VARISTOR 1.05KV 40KA BLADE ENCAS	3
V14H140P Wickmann / Littelfuse	VARISTOR 220V 6.5KA DISC 14MM	0
V05P42AUTO Wickmann / Littelfuse	VARISTOR 68V 400A DISC 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