TVS - Varistors, MOVs

Part Number	Description / PDF	Quantity
RV391K05T Stackpole Electronics, Inc.	VARISTOR 390V 400A DISC 5MM	0
ZV50K1812T401N Stackpole Electronics, Inc.	VARISTOR 82V 400A 1812	0
RV271K10T Stackpole Electronics, Inc.	VARISTOR 270V 2.5KA DISC 10MM	0
ZV40K2220T102N Stackpole Electronics, Inc.	VARISTOR 68V 1KA 2220	0
RV471K14T Stackpole Electronics, Inc.	VARISTOR 470V 4.5KA DISC 14MM	0
ZV130K1812T301N Stackpole Electronics, Inc.	VARISTOR 205V 300A 1812	470
ZV50K2220T801N Stackpole Electronics, Inc.	VARISTOR 82V 800A 2220	1999
RV221K10T Stackpole Electronics, Inc.	VARISTOR 220V 2.5KA DISC 10MM	0
ZV30K2220T122N Stackpole Electronics, Inc.	VARISTOR 47V 12KA 2220	15704000
PV300K4032T Stackpole Electronics, Inc.	VARISTOR 470V 1.2KA 2SMD JLEAD	17000
ZV17K1210T401N Stackpole Electronics, Inc.	VARISTOR 27V 400A 1210	0
ZV95K1812T301N Stackpole Electronics, Inc.	VARISTOR 150V 300A 1812	0
PV275K4032T Stackpole Electronics, Inc.	VARISTOR 430V 1.2KA 2SMD JLEAD	9
ZV14K1206T201N Stackpole Electronics, Inc.	VARISTOR 22V 200A 1206	0
RV511K14T Stackpole Electronics, Inc.	VARISTOR 510V 4.5KA DISC 14MM	0
RV471K07T Stackpole Electronics, Inc.	VARISTOR 470V 1.2KA DISC 7MM	0
ZV20K1210T401N Stackpole Electronics, Inc.	VARISTOR 33V 400A 1210	0
RV511K10T Stackpole Electronics, Inc.	VARISTOR 510V 2.5KA DISC 10MM	0
ZV35K1812T601N Stackpole Electronics, Inc.	VARISTOR 56V 600A 1812	0
RV621K14T Stackpole Electronics, Inc.	VARISTOR 620V 4.5KA DISC 14MM	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