Transcript TVS_web

Transient
Voltage Protection
By Curt Olsen
Director of Marketing & Sales, Scottsdale Division
Coordinating Activity for Transient Voltage Protection Products
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The Circuit Protection Applications
Protection from:
• Induced Lightning Spikes
• Electrostatic Discharge (ESD)
• Electrical Fast Transients (EFT)
• Load Switching Spikes
• NEMP Disturbances
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Overview of the Damaging Effects
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Lightning is the most obvious threat, heralding its presence with bright flashes across the sky and raucous thunder.
Powerful lightning strokes usually cause damage by inducing currents into both power and communication lines.
Direct hits are rare. Specific information on threats are defined in IEC 1000-4-5, ANSI C62.41, FCC 195528 Part 68
and AIRINC DO-160C. These documents include both conducted and radiated threats. Worst case transients are
more than 1 kA, with the low end of the spectrum at tens of amps. Occurring in multiple discharges, lightning
typically has two to three strokes per flash but can range up to twenty for severe events. Although extensive data
has been compiled to predict the flash density per square kilometer, lightning is predictably unpredictable, hence it
is virtually impossible to know where the next strike will hit.
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Load switching is the silent killer, producing spikes (L(di/dt) effects) as described by Faraday’s laws of induction.
Spike voltages can range from tens of volts to several thousand with associated short circuit currents from a few
amps to greater than 200 A. Bursts can occur from resonance producing closely spaced, repetitive 2 kV spikes or
“electrical fast transients” as defined in IEC 1000-4-4. Other documents defining induced transients are found in
MIL-PRF-704, DOD-PRF-1399 and AIRINC DO-160C. Many laboratory and field observations support the
conditions stated in these standards. The writer has observed 0.5 us, 1500 V closely spaced multiple voltage spikes
while de-energizing relays. When your power fails, energy stored in inductive loads such as transformers and
motors is dumped into the utility line. This produces spikes which can latch up controls on appliances.
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Electrostatic discharge (ESD) is the insidious killer that can zap a microchip with a spike of only 2 kV, well below the
threshold of perception of the finger tip. Worst case values are 15 kV or more delivering 30 A. This threat is
described in IEC 1000-4-2. The aspect of this threat which makes it so devastating is its fast rise time, in the
subnanosecond range, with values reported as low as 100 picoseconds. Contacting and separating two dissimilar
materials (leather shoe soles on wool carpeting or rubber sports shoes on tile) builds up an electric charge on both
surfaces. The generation of static electricity is heavily influenced by ambient humidity. At 10% relative humidity, the
amount of static build-up is about twice the level developed at 40%, and four times the level at 55%.
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Microsemi TVS Solutions
• Any package, any voltage, any power level
• All the “standard” solutions
– SMA/SMB/SMC/SML
– SOIC Arrays
– Axial
• plus:
– Low capacitance series
– Ultra low capacitance (USB)
– Low clamping voltage
– Multiple die stacks and arrays
– Miniaturization
– Any application specific solution
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TVS Products - Market Size
FY98 SAM=$665,000
•Major competitors world wide
•GI/GSI
33%
•Motorola
33%
•Thomson 12%
•Philips
8%
•Teccor
5%
•Microsemi
4%
•Other
5%
•Market growth projected at 20%
4%
5%
5%
33%
8%
12%
GI/GSI
Motorola
Thomson
Phillips
Teccor
Microsemi
Other
33%
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TVS - Target Markets
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Aerospace - Chips, Cells, Hermetic Axial & SM
Automotive - Chips & Wafers, Melf, Load-Dump
Commercial - SM, Axial, Powermite, SOIC, USB, TSPD
Computer - USB, SOIC, Powermite, SM, Axial
Medical - Chips, Cells, Straps
Industrial - Modules, SOIC, SM, Axial, Load-Dump
Military - Metal Can, Modules, Hermetic Axial & SM
Telecom - Powermite, SM, Axial, MSV (varistors), SMCLCE, TSPD
We have products for every market!
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TVS-Product Portfolio
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TVS Diodes
– Axial glass and plastic to 20kW
– Surface mount glass and plastic to 3kW
– Low cap and low voltage series
TVSArrays
– Standard and low capacitance
– SO8 and SO16 packages
USB TVSArray SO8
– Ultra low capacitance
– High frequency, low attenuation
TVS Modules
– Up to 1,000,000 watts per cubic inch
– Any shape and terminal configuration
TSPD “crowbar” Diodes
– Plastic axial and surface mount
– Standard products at 50A and 100A
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TVS Diodes - Specifications
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Operating voltage: 3V thru 1000V
Stacking and parallel configurations available
Broad power rating: 150 watts thru 20kW
Unipolar and bipolar configurations
Low capacitance axial and surface mount
Low clamping voltage series, axial and surface mount
Packages:
– Axial glass and plastic
– Surface mount glass and plastic
– Powermite (soon Powermite 2)
– Chips, cells, Arrays
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TVS Diodes - Thrust Products
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SMA 500 watt plastic surface mount
SMB 600 watt plastic surface mount
SMC 1500 watt plastic surface mount
SML 3000 watts in an SMC package
Powermite 150 watt miniature plastic SM
P3K3.0 low voltage series
SMCLCE low cap, 1500 watt TVS
Chips, Cells, Arrays, for hybrid applications
SMA, SMB Zener Diodes
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TVS Diodes - Thrust Product
Advantages
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SMA
– Thermally superior to competition
– Rated at 500 watts
SML
– Only one viable competitor
– 3000 watts in a 15 watt package
Powermite
– Only one competitor
– Smallest size TVS available
SMCLCE
– world’s only supplier
Chips
– Total wafer fab control
– Time to market
Price competitive!
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TVS Die for Hybrids
• Chips from .020 inch to .320 inch square
• Unipolar or bipolar configurations
• Disk-die-disk (cells) available
– 100% clamp tested
– Any polarity uni- or bipolar
– Any metallization top & bottom
• FlipChips for C.O.B. applications
• Strap assemblies and arrays
• Commercial or Hi-Rel (JANKC) available
TVS Diodes - New Products
• Powermite 2
– 1500 watt TVS
– Maintain PCMCIA height specification
– Samples available in September
• P3K3.0-5.0
– Low operating and clamping voltage (3-5 Volts)
– Samples available now
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SOIC TVSArraysTM
Capability
•3.3V thru 36V+
•Unipolar and Bipolar configurations
•Low capacitance series
•Any GI, Semtech, Protek socket
•We Target SMDA and SMDB sockets
•ESD protection (multi-line)
•Commercial, Computer, Industrial markets
Thrust Products
•USB 0805C
•SMDA, SMDB
•SMDAXXC-5
•SMDAXXC-6
•SMDAXXC-7
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TVS Array Options
1
16
2
15
3
14
4
13
5
12
6
11
7
10
8
9
1
2
16
15
3
14
4
13
1
16
2
15
3
14
4
13
5
12
6
11
5
12
7
10
6
11
8
9
7
10
8
9
1
GND
2
N .C .
3
N .C .
4
5
1
16
2
15
3
14
4
13
5
12
6
11
7
10
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9
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USB08XX SOIC TVSArrays
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Capacitance of <5pF per line
Nanosecond response time
Low parasitic inductance
300Watt peak pulse power @8/20uS
Leakage <50nA @ 3.5V
SO-8 surface mount package
Microsemi
Semtech
Semtech
TI
Part
USB0803C
USB0805C
USB0812C
USB0815C
USB0824C
Voltage DatasheetID
3.3 Volts
24479
5 Volts
24197
12 Volts
24480
15 Volts
24481
24 Volts
24482
USB08 Series
$1.40/10K pcs
SL05-SL24(SOT-23) $0.50??
LCDA or SRDA Series$1.50/10K pcs
TUSV Series
$1.00/10K pcs
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TVS Modules
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Power levels exceeding 1,000,000 watts per cubic inch
Focus on custom configurations
Unipolar or bipolar configurations
Low capacitance versions available
Second source all GSI modules
Microsemi is the primary supplier of lightning strike protection
modules to the commercial avionics industry.
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TSPD Diodes
Secondary lightning protection for:
Communication and control lines
•Central office systems
•PABX’s
•Subscriber station protectors
•Related peripherals
•Modems
•Cable connectors
Unique Advantages:
•Voltage triggered
•Low on-state “crowbar” voltage
•High current capability (up to 200A)
•Positive slope V(BO)
•Minimize false triggering or
partial turn-on
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Target End Applications
• Computers/Peripherals
– USB Applications
– Modems
– Printers
• Battery Chargers
• IC Protection
• Lightning Protection
• Mil/Aero Solutions
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Selecting a TVS Diode
• What peak surge power is required (watts vs time)
• Stand off voltage equal to or greater than the normal
circuit operating voltage
• Clamping voltage below the voltage that could cause
damage to the protected component
• Unipolar or bipolar configurations
• Microsemi has over 12,000 TVS
device types
• You can find the part you need by
using our selection guide tools or
by using the TVS Cross
Reference Guide.
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Universal Serial Bus
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Over 60% of the field failures of High Speed CMOS devices such as those
used in the USB are destroyed by ESD
Most of these devices (almost 90%) are destroyed at ESD levels of less
than 2KV
3KV can easily pass through your finger without notice
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Battery Chargers
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Forward AC/DC Converter-charger (Sample Circuit)
– Cellular Phones
– Laptops/Notebooks
1Amp,
20V or 40V
SCHOTTKY
LOAD
600W
TVS
SYNC
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IC Protection
• ESD is the threat
• Our solutions:
– SMA/SMB/SMC/SML
– Powermite TVS
– Powermite Zeners
– SOIC Arrays
– Flip Chips
– Cells
– MELF TVS
– Standard Zener Diodes
• We offer selective versions of:
– SOT23
– SOD123
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Lightning Protection
• Conducted Threats
• Radiated Threats
• Solutions:
– TSPD “Crowbar” Diodes
– Modules
– Clamping Diodes
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Mil/Aero Solutions
• JANTX/TXV 1500 Watt Metal Axial
• Modules
– JANTX/TXV Subassemblies
– JANTX/TXV Equivalent Screening
on Module
– Both
• Chips and cells for hybrid applications
• Complete line of military and space
level products available from both
Santa Ana and Scottsdale.
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Application Summary
• Any place a design needs to protect from a Transient Voltage or
Current Spike…we have the products.
• Any place where space/size is critical.
• Any place where “the big guys” have left them
hanging…Microsemi has the infrastructure to respond quickly.
• Diversity, diversity, diversity…we have products for all
applications - from heart pacers to laptops.
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Zener Diodes
New Products
•SMAJ4728-4764A
•SMAJ5913-5956B
•SMBJ5333-5388B
•10EZ 3,9-100B
•MMBZ5226-5261B
•BZX84C3V3-C47
2 Watt, SMAJ
3 Watt, SMAJ
5 Watt, SMBJ
10 Watt, TO-220
SOT23
SOT23
New Products for FY98
•Powermite Zeners
•BZY93
–DO4
–10 Watt Stud
•BZY91
–DO5
–100 Watt stud
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New Brochure
A new brochure outlining or TVS
capabilities is now available.
A complimentary website to the
new brochure exists at:
http://www.microsemi.com/TVS/
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TVS FAQs
• Are there application notes for TVS?
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A primer on transient voltage
An introduction to transient voltage suppressor devices
What is a silicon transient voltage suppressor
Using the power vs time curve
What is a thyristor surge protector device
Crowbars and clamps
Cross referencing TVS devices
Determining a range of clamping voltages for a range of pulse currents
Protecting from electrostatic discharge
Parasitic capacitance in transient voltage suppressors
Parasitic lead inductance on transient voltage
Series stacking of silicon TVSs for higher surge current
Parallel stacking of silicon TVSs for higher surge current
Derating of silicon TVSs for higher junction temperatures
Derating transient voltage suppressors at elevated temperatures for
varying pulse widths
Protection at a transformer
Protecting USB data I/O ports
TVS/Chip product overview
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