Introduction to TVS Overvoltage Protection Devices

Introduction to TVS Overvoltage

Protection Devices

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Outline

Overvoltage Protection– The race is on– Clamp vs Crowbar

Key Parameters– Unidirectional vs Bidirectional– Peak Pulse Power PPPM

– Double Exponential Waveforms

– Reverse Stand-Off Voltage VR– Breakdown Voltage VBR– Clampin Voltage VC– Peak Pulse Current IPP

Product Families– Part Number Conventions– Axial Leaded

P4KE, SA, SAC, P6KE 1.5KE, LCE 3KP, 5KP, SLD 15KPA, 20KPA, 30KPA AK6, AK10

– Surface Mount SMAJ, P4SMA, SACB SMBJ, P6SMB, 1KSMB SMCJ, 1.5SMC SMDJ, 5.0SMDJ

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The Race is On!

Overvoltage Protector

Protected Circuit

Overvoltage Event

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Vline

Trigger Voltage

Delatch

Crowbar Devices

Vline

Transient Event

Vline

Clamping Devices

Clamp Voltage

Clamping Devices vs Crowbar Devices

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Outline




– Reverse Stand-Off Voltage VR– Breakdown Voltage VBR– Clamping Voltage VC– Peak Pulse Current IPP


P4KE, SA, SAC, P6KE 1.5KE, LCE 3KP, 5KP, SLD 15KPA, 20KPA, 30KPA AK6, AK10

– Surface Mount SMAJ, P4SMA, SACB SMBJ, P6SMB, 1KSMB SMCJ, 1.5SMC SMDJ, 5.0SMDJ

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Key Parameters: Peak Pulse Power

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Key Parameters: Peak Pulse Power

Double Exponential Waveforms– Simulate induced lightning events– Rise time & decay time in microseconds

Underground LineUnderground Line

Transients

Transients

Transients

Transients

10 x 10008 x 20

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Bidirectional vs Unidirectional

Bidirectional TVS Unidirectional TVS

Voltage – Current (V-I) Curve

• Voltage is displayed left to right

• Current is displayed up and down

+I

+V-V

-I

IPP

IT

VR VBR VC

IR

+I

+V-V

-I

IPP

IT

VR VBR VC

IR

+I

+V-V

-I

IPP

IT

VR VBR VC

IR

+I

+V-V

-I

IPP

IT

VR VBR VC

IR

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+I

+V-V

-I

IPP

IT

VR VBR VC

IR

Key Parameters: VR

Reverse Standoff Voltage

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+I

+V-V

-I

IPP

IT

VR VBR VC

IR

Key Parameters: VBR

Breakdown Voltage

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+I

+V-V

-I

IPP

IT

VR VBR VC

IR

Key Parameters: VC

Max Clamping Voltage

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Key Parameters: Ipp

+I

+V-V

-I

IPP

IT

VR VBR VC

IR

Peak Pulse Current

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Question 1: True or False

A TVS Diode is intended to provide continuous voltage regulation to a circuit.

FALSE

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A TVS Diode is a crowbar type of device that brings the protected line close to ground potential.

FALSE

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The continuous power rating of a TVS Diode can be found by multiplying the peak allowable pulse current by the clamping voltage.

FALSE

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A bidirectional TVS Diode can be used on a DC line.

TRUE

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A Unidirectional TVS Diode is symmetrical and has the same clamp voltage regardless of the direction of current flow through the part.

FALSE

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Outline




– Reverse Stand-Off Voltage VR– Breakdown Voltage VBR– Clamping Voltage VC– Peak Pulse Current IPP


– P4KE, SA, SAC, P6KE– 1.5KE, LCE– 3KP, 5KP, SLD– 15KPA, 20KPA, 30KPA– AK6, AK10

– Surface Mount– SMAJ, P4SMA, SACB– SMBJ, P6SMB, 1KSMB– SMCJ, 1.5SMC– SMDJ, 5.0SMDJ

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Part Numbering Conventions

• The first portion: Indicates the Peak Pulse Power or the package or both.

• The next portion: Indicates either the VR or the nominal VBR

• Both voltage conventions are industry standards.

• Offering both conventions is a critical driver for sales.

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Part Numbering Conventions

VR – Based Part Numbers – Axial Leaded

SA, SAC, LCE 3KP, 5KP, SLD 15KPA, 20KPA, 30KPA AK6, AK10

– Surface Mount SMAJ, SACB SMBJ, SMCJ, SMDJ, 5.0SMDJ

VBR – Based Part Numbers– Axial Leaded

P4KE, P6KE 1.5KE,

– Surface Mount P4SMA, P6SMB, 1KSMB 1.5SMC

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Axial Leaded TVS Diodes

Available Axial Packages

DO-41 DO-15 DO-201 P-600

AK-6 AK-10

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DO-41 Axial TVS Diodes

P4KE (400W)

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P6KE (600W) SA (500W) SAC (500W, Low Cap)

TVS Diode

Isolation Diode

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1.5KE (1500W) LCE (1500W, Low Cap)

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P-600 Axial TVS Diodes

3KP (3000W) 5KP (5000W) 15KPA (15000W) 20KPA (20000W) 30KPA (30000W) SLD (2200W - 100x150000 uS Waveform)

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AK Series TVS Diodes

AK6 (6000A – 8x20 uS Waveform) AK10 (10000A – 8x20 uS Waveform)

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Surface Mount TVS Diodes

Available Surface Mount Packages

DO-214AC(SMA J-Bend)

DO-214AA(SMB J-Bend)

DO-214AB(SMC J-Bend)

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SMA Surface Mount TVS Diodes

SMAJ (400W) P4SMA (400W)

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SMB Surface Mount TVS Diodes

SMBJ (600W) P6SMB (600W) SACB (500W, Low Cap) 1KSMB (1000W)

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SMC Surface Mount TVS Diodes

SMCJ (1500W) 1.5SMC (1500W) SMDJ (3000W) 5.0SMDJ (5000W)

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Axial TVS Diode Summary

Naming Convention

Polarity DO-41 DO-15 DO-201 P-600 AK

Vbr P4KE P6KE 1.5KE

SA

3KP5KP

15KPA20KPA30KPA

SLD

AK6AK10

Low Cap SAC LCE

Vr

Uni / Bi

Littelfuse Axial TVS Diodes

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Surface Mount TVS Diode Summary

Naming Convention

Polarity SMA SMB SMC

Vbr P4SMAP6SMB1KSMB

1.5SMC

SMAJ SMBJSMCJSMDJ

5.0SMDJ

Low Cap SACB

Uni / Bi

Vr

Littelfuse Surface Mount TVS Diodes

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The leakage current of a TVS Diode is measured at its breakdown voltage.

FALSE

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If the same pulse current is allowed to flow through both a low power and a high power TVS Diode, the clamping voltage will be lower on the high power device.

TRUE

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If a narrow 20µS current pulse is allowed to flow through a TVS Diode, the allowable power level can be higher than the 10x1000µS power level indicated on the data sheet.

TRUE

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The AK series of TVS Diodes can handle a million watts of power during a transient event.

TRUE

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TVS Diode part numbers always refer to the actual breakdown voltage of the device.

FALSE

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Thank You!

Introduction to TVSOvervoltage Protection Devices

Introduction to TVS Overvoltage Protection Devices

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