Telecom SIDACtor Training
Confidential and Proprietary to Littelfuse, Inc.
© 2007 Littelfuse, Inc. All rights reserved.
1

Telecom SIDACtor Training
•
SIDACtor Definition
– A SIDACtor is a thyristor-based protection device that provides a crowbar current path to protect electronic components/equipment from transient threats
• Circuit Protection Needs in Telecom Segment
– Lightning
– ESD
– Inductive
–
Short Circuit/Power-Cross
•
SIDACtor Technology for Telecom Overcurrent Circuit Protection
–
Fast response time
–
Stable electrical characteristics
• Typical Telecom Test Standards
– ITU K.20 K.21
– Bellcore GR1089
– UL 60950
• Typical SIDACtor Test Standards
– IEEE C62.37
– UL 1449
–
UL 1459
Confidential and Proprietary to Littelfuse, Inc.
© 2007 Littelfuse, Inc. All rights reserved.
2

SIDACtor Definition and Telecom Circuit Protection
SIDACtor Definition
– SIDACtor is a thyristor-based protection device that provides a crowbar current path to protect electronic components from transient threats.
– The SIDACtor functions:
• Bi-directional, voltage-triggered switch
• Normally open circuit (high impedance)
• Turns on with trigger voltage
• On-state becomes low-impedance path
• Turns off when current falls below holding level
– SIDACtor features as following
• Cannot be damaged by transient voltage.
• Eliminates the hysteresis and heat dissipation typically found with a clamping device.
• Eliminates voltage over-shoot caused by fast rising transients / Extremely fast (<10 ns).
• Non-degenerative, will not fatigue / Rugged (Up to 5,000A surge current ratings).
• Relatively low capacitance, ideal for high speed transmission equipment.
Confidential and Proprietary to Littelfuse, Inc.
© 2007 Littelfuse, Inc. All rights reserved.
3

SIDACtor Definition and Telecom Circuit Protection
Circuit Protection Needs in Telecom Systems
– Thunderstorms around the world deliver 8 million lightning flashes every day. Peak current in lightning discharges range from a few KA to many hundreds of KA. Induced currents from indirect strikes range from 10A to 20KA.
– ESD results from the build up of electrical charge, when two non-conductive materials are brought together then separated. The potential between a human body & an object can exceed 35,000 volts.
An ESD event can occur to the telecom system or portable devices through human contact and usage of the telecom devices.
– Inductive Load Switching is caused when an inductive load is interrupted. It occurs in factory/industrial environments where motors and relays (inductive loads) are turned on and off.
– Short Circuit or Power Cross events can occur due to human error (such cutting a phone and power line simultaneously during construction) or natural disaster such as hurricane, thunderstorm.
– One or a combination of the above threats can have obvious adverse effects on semiconductor/IC devices, electro-mechanical contacts, wiring insulation, etc., to cause interruption of telecom equipment operation, telephone service, and even fire.
Confidential and Proprietary to Littelfuse, Inc.
© 2007 Littelfuse, Inc. All rights reserved.
4

SIDACtor Definition and Telecom Circuit Protection
SIDACtor Technology for Telecom Overvoltage Circuit Protection
Telecom equipment should be protected from overvoltage conditions using SIDACtors, GDTs,
MOVs, or TVS diodes.
– A SIDACtor device is a PNPN device that can be thought of as a TVS diode with a gate. Upon exceeding its peak off-state voltage (V
DRM
), a SIDACtor device will clamp a transient voltage to within the device's switching voltage (V
S
) rating. Then, once the current flowing through the
SIDACtor device exceeds its switching current, the device will crowbar and simulate a short-circuit condition. When the current flowing through the SIDACtor device is less than the device's holding current (I
H
), the SIDACtor device will reset and return to its high off-state impedance.
– SIDACtor devices are primarily used as the principle overvoltage protector in telecommunications and data communications circuits. Its advantages include:
• Fast response time
• Stable electrical characteristics
• Long term reliability (no wear-out mechanism)
• Low capacitance
• It is difficult to be damaged by voltage and it has extremely high surge current ratings.
– The SIDACtor is a crowbar device, it cannot be used directly across the AC line; it must be placed behind a load. Failing to do so will result in exceeding the SIDACtor device's surge current rating, which may cause the device to enter a permanent short-circuit condition.
Confidential and Proprietary to Littelfuse, Inc.
© 2007 Littelfuse, Inc. All rights reserved.
5

SIDACtor Definition and Telecom Circuit Protection
Telecom Systems Standards
GR 974
K.20 YD/T 950
UL 497
GR 974
GR 1089
K.20 YD/T 1082
NEC 800
UL 497
SLIC
MDF
GR 1089
K.20 YD/T 950
UL 60950
GR 974
GR 1089
K.21 YD/T 993
NEC 800
UL 497
GR 974
K.20/21
YD/T
950/993
UL 497
Confidential and Proprietary to Littelfuse, Inc.
© 2007 Littelfuse, Inc. All rights reserved.
6

SIDACtor Definition and Telecom Circuit Protection
SIDACtor Standards
– Std C62.37 Specification
• Rated parameter values
– The values of the rated parameters are established by the manufacturer.
• Parameter specifications
– Breakover current (I
BO
)
– Breakover voltage (V
BO
)
– Holding current (I
H
)
– Non-repetitive peak on-state current (Itsm)
– Non-repetitive peak pulse current (Ipps)
– Off-state capacitance (C
O
)
– Off-state (leakage) current (I
D
)
– Off-state voltage (V
D
)
– On-state current (I
T
)
– On-state voltage (V
T
)
– Repetitive peak off-state current (I
DRM
)
– Repetitive peak off-state voltage (V
DRM
)
– Repetitive peak on-state current (I
TRM
)
Confidential and Proprietary to Littelfuse, Inc.
© 2007 Littelfuse, Inc. All rights reserved.
7

Telecom SIDACtor Training
–
•
•
•
Basic SIDACtor Characteristics and test procedures
Electrical Characteristics
– V-I curve Characteristics
– di/dt, dV/dt
– Maximum ratings
– Continuous / Transient
Thermal Characteristics
–
Junction Temperature
Signal Integrity Characteristics
–
Capacitance
–
•
•
•
•
SIDACtor Device Physics
SIDACtor Construction and V-I Curve Types
SIDACtor Thermal Effects/Characteristics
SIDACtor Capacitance Effects
SIDACtor Peak Pulse Current
Confidential and Proprietary to Littelfuse, Inc.
© 2007 Littelfuse, Inc. All rights reserved.
8

SIDACtor Characteristics and Device Physics
V-I Curve and Device Operation
In the standby mode, SIDACtor devices exhibit a high off-state impedance, eliminating excessive leakage current and appearing transparent to the circuits they protect. Upon application of a voltage exceeding the switching voltage (V
S
), SIDACtor devices crowbar and simulate a short circuit condition until the current flowing through the device is either interrupted or drops below the SIDACtor device's holding current (I
H
). Once this occurs, SIDACtor devices reset and return to their high off-state impedance.
V
S
(Switching Voltage)
V
DRM
(Peak Off-state Voltage)
V
T
(On-state Voltage)
I
T
(On-state Current )
I
S
(Switching Current )
I
H
(Holding Current )
I
DRM
(Leakage Current )
Maximum voltage prior to switching to on state
Maximum voltage that can be applied while maintaining off-state
Maximum voltage measured at rated on-state current.
Maximum rated continuous onstate current
Maximum current required to switch to on-state
Minimum current required to maintain on-state
Maximum peak off-state current measured at V
DRM
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© 2007 Littelfuse, Inc. All rights reserved.
9

SIDACtor Characteristics and Device Physics
– di/dt Rate of Rise of Current
-- Maximum value of the acceptable rate of rise in current over time
The purpose of this test is to verify that the
SIDACtor can survive a fast rising current, as may occur on the wave front of an impulse. After applying the di/dt impulse to the device, and when it has returned to thermal equilibrium conditions, the device shall not fail any of its specified characteristics.
– dV/dt Rate of Rise of Voltage
-- rate of applied voltage over time
The purpose of this test is to verify that the
SIDACtor will not turn on as a result of fast rising system voltages with peak amplitudes lass than the Vdrm rating. A specified voltage ramp equal to the minimum value of critical dv/dt and of amplitude Vdrm shall be applied to the un-energized DUT. The peak ramp voltage shall be maintained for a period of at least
50us. The DUT shall not switch on, even partially, during the test.
Confidential and Proprietary to Littelfuse, Inc.
© 2007 Littelfuse, Inc. All rights reserved.
10

SIDACtor Characteristics and Device Physics
Maximum Ratings
– I
PP
-- Peak Pulse Current
The purpose of this test is to verify that the
SIDACtor can survive a specific impulse wave shape of short circuit current amplitude I
PP failure. The impulse test generator shall be with out specified for the open-circuit voltage and shortcircuit current values, or equivalents, of wave shape and wave shape peak value.
Confidential and Proprietary to Littelfuse, Inc.
© 2007 Littelfuse, Inc. All rights reserved.
11

SIDACtor Characteristics and Device Physics
Thermal Characteristics
– Thermal Resistance
The purpose of this test is to determine the continuous power capability of the SIDACtor.
Immediately prior to the power being applied, the value of a temperature dependent characteristic shall be measured at the reference temperature. A constant value of power is then applied to the device.
Thermal resistance, junction to ambient
R өJA
= (T
JPK
- T
A
) / P
TOT
°C / W
Thermal resistance, junction to case
R өJC
= (T
JPK
- T
C
) / P
TOT
°C / W
Thermal resistance, junction to lead
R өJD
= (T
JPK
- T
L
) / P
TOT
°C / W
Where T
A
= ambient temperature
T
C
= case temperature
T
L
= lead temperature
T
JPK
= peak junction temperature
P
TOT
= power pulse amplitude
Confidential and Proprietary to Littelfuse, Inc.
© 2007 Littelfuse, Inc. All rights reserved.
12

SIDACtor Characteristics and Device Physics
Off- State Capacitance
– C
O
The purpose of this test is to determine the off-state capacitance of the SIDACtor under specified conditions.
The DUT off-state capacitance, C
O
, shall be measured at specified dc (V
D
) and ac (V
D and V
F
) bias levels.
In the absence of special requirements, it is recommended that an AC bias level of V
D
=
0.1 V
RMS at a frequency of 100kHz to 1 MHz be used. The DC bias level should be 0 V and any other levels that are representative of the intended application.
Confidential and Proprietary to Littelfuse, Inc.
© 2007 Littelfuse, Inc. All rights reserved.
13

SIDACtor Characteristics and Device Physics
SIDACtor Construction
SIDACtors are manufactured by creating a series of N-type and P-type layers in a silicon chip. The basic thyristor structure has three PN junctions that require four layers (NPNP).
The SIDACtor device started manufacture with an N- slice of silicon. Layers of P material are then created at the top and the bottom. A further N+ region is then made on the top surface. Finally the top and the bottom metallization are added to provide contacts.
Transistor TR1 is formed by the N+PN- layers. Similarly transistor TR2 is formed by the PN-P layers. The device breakdown voltage is determined by the breakdown of the central N-P layers, which form a shared collector-base junction for TR1 and TR2. The breakdown function is shown as D1. R1 is the lateral resistance of the P layer. R2 together with R1 shunt the base-emitter junction of TR1 to define the value of holding current Ih. R2 has a relatively low value of resistance and is considered as a localized short circuit between base and emitter.
During the manufacturing process, the emitter N+ diffusion is perforated with a series of dots to create these short circuits. On the picture, some of the top metallization has been omitted to show the P-type shorting dots.
Confidential and Proprietary to Littelfuse, Inc.
© 2007 Littelfuse, Inc. All rights reserved.
14

SIDACtor Characteristics and Device Physics
SIDACtor Types
Unidirectional Blocking
SIDACtor
The inherent (fixed) voltage breakdown can be lowered by gate control, either by use of a single gate or both together.
In the non-switching quadrant, current flow will be blocked by the reverse N-P anode junction.
Unidirectional Conducting
SIDACtor
The inherent (fixed) voltage breakdown can be lowered by gate control, either by use of a single gate or both together.
In the non-switching quadrant, current flow will be blocked by the reverse PN diode.
Confidential and Proprietary to Littelfuse, Inc.
© 2007 Littelfuse, Inc. All rights reserved.
15

SIDACtor Characteristics and Device Physics
SIDACtor Types
Bidirectional SIDACtor
The inherent (fixed) voltage breakdown can be lowered by controlling the appropriate gate or gates.
Bidirectional TRIAC SIDACtor
This bidirectional TRIAC has a special gate structure that permits control in both quadrants with a single gate terminal.
Confidential and Proprietary to Littelfuse, Inc.
© 2007 Littelfuse, Inc. All rights reserved.
16

SIDACtor Characteristics and Device Physics
SIDACtor Thermal Effects
Confidential and Proprietary to Littelfuse, Inc.
© 2007 Littelfuse, Inc. All rights reserved.
17

SIDACtor Characteristics and Device Physics
SIDACtor Thermal Effects
Confidential and Proprietary to Littelfuse, Inc.
© 2007 Littelfuse, Inc. All rights reserved.
18

SIDACtor Characteristics and Device Physics
SIDACtor Capacitance Effects
Confidential and Proprietary to Littelfuse, Inc.
© 2007 Littelfuse, Inc. All rights reserved.
19

SIDACtor Characteristics and Device Physics
SIDACtor Non- Repetitive Peak Pulse Current
I
PP rating can be expressed as specific peak impulse current -time values or with a graph. If the designer ensures that the SIDACtor is always operated below this limiting value, protector failure will not occur.
Confidential and Proprietary to Littelfuse, Inc.
© 2007 Littelfuse, Inc. All rights reserved.
20

Telecom SIDACtor Training
–
•
Basic Protection Topology
Two Point and Three Terminal Telecom Circuit Protection
–
•
•
•
•
Circuit Protection based on Telecom Application Requirement
Customer Premises Equipment
– Transformer-Coupled Tip and Ring Circuits
High Speed Transmission Equipment & Interfaces
–
ADSL
–
T1/E1 Protection
–
IDSN
Analog Line Cards
–
SLIC Protection
Data Line Protection
– LAN/WAN Protectors
–
•
•
•
•
Littelfuse Global Lab Capabilities
Qualification of Products
UL-Approved Customer Testing
Verification of Standards
Customer Application Testing
Confidential and Proprietary to Littelfuse, Inc.
© 2007 Littelfuse, Inc. All rights reserved.
21

SIDACtor Telecom Applications Protection Examples
Basic SIDACtor Topology
Two-terminal parallel connected unit
Three-terminal parallel and delta connected unit
Protector with bridge diodes for wide band systems
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© 2007 Littelfuse, Inc. All rights reserved.
22

SIDACtor Telecom Applications Protection Examples
Primary Protection
Primary protection is provided by the local exchange carrier and can be segregated into three distinct categories as station protection, building entrance protection, and central office (CO) protection.
Protection Requirements
Station protectors must be able to withstand 300A 10x1000 surge events. The building entrance protectors and
CO protectors must be able to withstand 100A 10x1000 surge events. It should meet regulatory standards such as UL 497, GR974-CORE and ITU K.28.
Example: Primary Protection Example: Balanced Primary Protection
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© 2007 Littelfuse, Inc. All rights reserved.
23

SIDACtor Telecom Applications Protection Examples
Customer Premises Equipment (CPE)
CPE is defined as any telephone terminal or network equipment which resides at the customer's site and is connected to the Public Switched Telephone Network (PSTN)
Protection Requirements:
CPE should be protected against overvoltages that can exceed 800V and against surge currents up to 100A. It should meet regulatory standards such as TIA -IS-968 and UL 60950
Example: Basic CPE (Phone, Modem) Protection Application
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24

SIDACtor Telecom Applications Protection Examples
High Speed Transmission Equipment & Interfaces
High speed transmission equipment encompasses a broad range of transmission protocols such as T1/E1, xDSL, and ISDN. Transmission equipment is located at the central office, customer premises, or remote locations.
Protection Requirements:
High speed transmission equipment should be protected against overvoltages that can exceed 2500V and against surge currents up to 500A. It should meet regulatory standards such as TIA -IS-968, GR 1089-CORE, ITU
K.20/K.21, and UL 60950
Example: T1/E1 Protection Application
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25

SIDACtor Telecom Applications Protection Examples
Analog Line Cards
Subscriber Line Interface
Cards (SLICs) are highly susceptible to transient voltages that occur at the central office and in remote switching locations.
Protection Requirements
It is often necessary to protect Analog line cards by on-hook (relay) and offhook (SLIC) protection. It should meet regulatory standards such as TIA -IS-
968, GR 1089-CORE, ITU K.20/K.21, and UL 60950.
Example: SLIC Protection
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26

SIDACtor Telecom Applications Protection Examples
Data Line Protection
In many office and industrial locations, data lines such as RS-232, Ethernet, and AC power lines run in close proximity to each other, which often results in voltage spikes being induced onto data lines, possibly causing damage to sensitive equipment.
Protection Requirements
Data lines should be protected against overvoltages that can exceed 1500V and surge currents up to 50A.
Example: 10 Base-T Longitudinal Protection Application
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27

SIDACtor Telecom Applications Protection Examples
Gate Controlled (Programmable) Protection Thyristor (Battrax)
Unidirectional gate-controlled protectors
Positive and negative gatecontrolled protection
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28

SIDACtor Telecom Applications Protection Examples
Global Lab Capabilities
•
Qualification of all LF products
•
UL-Approved Customer Testing in ISO 17025 Lab (Des Plaines)
– High power (AC/DC up to 1KV/50KA) UL approvals available in DP
– Telcordia approvals in DP planned (2008)
• Verification of Telcordia, ITU, IEC, FCC, and other industry, regulatory, and safety standards
–
Verification to various OC and OV standards
• Insure application meets standards before submitting for approval
• Customer Application testing
– Assistance with design-in and performance verification
•
Help with selection of appropriate technology and rating
– Application troubleshooting
• Assistance insuring proper OV/OC and primary/secondary protection coordination
– Competitive evaluations
•
Competitive or technology performance comparisons
–
Reliability & Tin Whisker data/testing
Confidential and Proprietary to Littelfuse, Inc.
© 2007 Littelfuse, Inc. All rights reserved.
29

•
Telecom SIDACtor Training
SIDACtor Selection
– Coordination of Protection
–
•
SIDACtor Unique Advantages Over Other Technologies
SIDACtor as a Crowbar Device
• SIDACtor Fast Response to Transients
–
•
•
•
SIDACtor Device Selection
Identify SIDACtor Switching Voltage Requirement
Identify SIDACtor IT Requirement
Identify SIDACtor De-Rating Requirement
Confidential and Proprietary to Littelfuse, Inc.
© 2007 Littelfuse, Inc. All rights reserved.
30

SIDACtor Telecom Applications Protection Examples
Coordination of Protection
Primary and secondary coordination
Coordination among secondary protective devices
Confidential and Proprietary to Littelfuse, Inc.
© 2007 Littelfuse, Inc. All rights reserved.
31

SIDACtor Telecom Applications Product Selection
SIDACtor Selection
Technology
Response Time
Capacitance
Current surge rating
Electrical
Characteristic
Application
SIDACtor
Fastest
Low
High
Stable
Principle over-voltage in telecom, datacom circuit
GDT
Slowest
As low as 1pF
As high as 500A for 200 impulses
Degrade with time
MOV
Slower response time
High
High
Telecom applications
TVS
Fast
Higher
Low
Fatigue after multiple pulses
Useful in AC applications
Stable
Secondary protection
Confidential and Proprietary to Littelfuse, Inc.
© 2007 Littelfuse, Inc. All rights reserved.
32

SIDACtor Telecom Applications Product Selection
SIDACtor Selection
Characteristics of Transient Voltage Suppressor Technology
Confidential and Proprietary to Littelfuse, Inc.
© 2007 Littelfuse, Inc. All rights reserved.
33

SIDACtor Telecom Applications Product Selection
SIDACtor Selection
Confidential and Proprietary to Littelfuse, Inc.
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34

SIDACtor Telecom Applications Product Selection
SIDACtor selection
• Off-State Voltage (V
DRM
)
– V
DRM of the SIDACtor device must be greater than the maximum operating voltage of the circuit the SIDACtor device is protecting.
– POTS (Plain Old Telephone Service) Application:
• 150 V
RMS
(maximum operating voltage) office battery) = 268.8 V
PK
, V
DRM

2 + 56.6 V (maximum DC bias of central
> 268.8V
– ISDN (Integrated Services Digital Network) Application:
– 150 V
PK
> 153V
(DC power supply) + 3 V
PK
(maximum voltage of the transmission signal), V
DRM
• Switching Voltage (V
S
)
– The V
S of the SIDACtor device should be equal to or less than the peak voltage rating of the component it is protecting
– Example 1: V
S
– Example 2: V
S
< Relay Breakdown Voltage
< SLIC (Subscriber Line Interface Circuit) V
PK
• Peak Pulse Current (I
PP
)
– The Surge Current Rating (I
PP
) of the SIDACtor device should be greater than or equal to the surge currents associated with the lightning immunity tests (I
PK
)
• I
PP
– R
TOTAL
> I
= R
PK
TIP
, I
+R
PP
>= I
SOURCE
PK
(Available) : I
(Longitudinal) R
PK
(Available) = V
TOTAL
= R
TIP
+R
PK
/R
TOTAL
RING
+R
SOURCE
(Metallic)
Confidential and Proprietary to Littelfuse, Inc.
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35

SIDACtor Telecom Applications Product Selection
SIDACtor selection
• Peak Pulse Current (I
PP
)
– Example 1: Type A surge requirement of TIA/EIA-IS-968(FCC Part 68) with out any series resistance
• I
PK
• I
PP
= 100A, 10x560 us
>= 100A, 10X560 us
• We can select "B","C" rated SIDACtor (page 2-4)
– Example 2: Surge requirement of GR 1089 with 30 ohm on Tip and 30 ohm on Ring.
• I
PK
• V
PK
= 100A, 10x1000 us
= 1000V, R
SOURCE
= V
PK
/ I
PK
= 10 ohm
• R
TOTAL
• I
PK
= R
SOURCE
(available) = V
+ R
TIP
PK
/R
= 40 ohm
TOTAL
= 1000V/40 ohm
• I
PP
>= 25A
• Holding Current (I
H
)
– The holding current (I
H
) of the SIDACtor device must be greater than the DC current that can be supplied during an operational and short circuit condition
– Example, TIA/EIA-IS-968 I
PK
<= 140 mA, IH = 150mA
• Off-State Capacitance (C
O
)
– If Insertion Loss is recommended 70% of the original signal value.
– Example, Speed >= 30MHz, new MC series is highly recommended.
Confidential and Proprietary to Littelfuse, Inc.
© 2007 Littelfuse, Inc. All rights reserved.
36

Telecom SIDACtor Training
–
•
•
Teccor Brand
SIDACtor Road Map
Battrax Road Map
–
•
•
Concord Brand
Fixed Voltage Protection Thyristor Road Map
Variable Voltage Protection Thyristor Road Map
Confidential and Proprietary to Littelfuse, Inc.
© 2007 Littelfuse, Inc. All rights reserved.
37

Telecom SIDACtor Training
– SIDACtor V
S and tolerance control
– Higher surge ratings and smaller packaging
– Multiple devices in one package
– SIDACtor technology combined with other technologies in the same package
– Improved de-rating characteristics
– Higher operating temperatures
– Development of programmable SIDACtors
– Lead-frame vs. wire-bonding
Confidential and Proprietary to Littelfuse, Inc.
© 2007 Littelfuse, Inc. All rights reserved.
38