Training Agenda - Littelfuse /media/electronics/...¢  Confidential and Proprietary to Littelfuse, Inc

  • View
    0

  • Download
    0

Embed Size (px)

Text of Training Agenda - Littelfuse /media/electronics/...¢  Confidential and Proprietary to...

  • 1 Confidential and Proprietary to Littelfuse, Inc. © 2007 Littelfuse, Inc. All rights reserved.

    Telecom SIDACtor Training

    Training Agenda

    1. SIDACtor Definition and Telecom Circuit Protection Needs

    2. SIDACtor Characteristics and Device Physics

    3. SIDACtor Telecom Applications Protection Examples

    4. SIDACtor Telecom Applications Product Selection

    5. Littelfuse SIDACtor Product Road Map

    6. SIDACtor Technology Challenges

  • 2 Confidential and Proprietary to Littelfuse, Inc. © 2007 Littelfuse, Inc. All rights reserved.

    Telecom SIDACtor Training

    Section 1 SIDACtor Definition and Telecom Circuit Protection

    • 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

  • 3 Confidential and Proprietary to Littelfuse, Inc. © 2007 Littelfuse, Inc. All rights reserved.

    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 (

  • 4 Confidential and Proprietary to Littelfuse, Inc. © 2007 Littelfuse, Inc. All rights reserved.

    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.

  • 5 Confidential and Proprietary to Littelfuse, Inc. © 2007 Littelfuse, Inc. All rights reserved.

    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 (VDRM), a SIDACtor device will clamp a transient voltage to

    within the device's switching voltage (VS) 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 (IH), 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.

  • 6 Confidential and Proprietary to Littelfuse, Inc. © 2007 Littelfuse, Inc. All rights reserved.

    SIDACtor Definition and Telecom Circuit Protection

    SLIC MDF

    GR 1089

    K.20 YD/T 950

    UL 60950

    GR 974

    K.20 YD/T 950

    UL 497

    GR 974

    GR 1089

    K.20 YD/T 1082

    NEC 800

    UL 497

    GR 974

    GR 1089

    K.21 YD/T 993

    NEC 800

    UL 497

    GR 974

    K.20/21

    YD/T

    950/993

    UL 497

    Telecom Systems Standards

  • 7 Confidential and Proprietary to Littelfuse, Inc. © 2007 Littelfuse, Inc. All rights reserved.

    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 (IBO)

    – Breakover voltage (VBO)

    – Holding current (IH)

    – Non-repetitive peak on-state current (Itsm)

    – Non-repetitive peak pulse current (Ipps)

    – Off-state capacitance (CO)

    – Off-state (leakage) current (ID)

    – Off-state voltage (VD)

    – On-state current (IT)

    – On-state voltage (VT)

    – Repetitive peak off-state current (IDRM)

    – Repetitive peak off-state voltage (VDRM)

    – Repetitive peak on-state current (ITRM)

  • 8 Confidential and Proprietary to Littelfuse, Inc. © 2007 Littelfuse, Inc. All rights reserved.

    Telecom SIDACtor Training

    Section 2 SIDACtor Characteristics and Device Physics

    – 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

  • 9 Confidential and Proprietary to Littelfuse, Inc. © 2007 Littelfuse, Inc. All rights reserved.

    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 (VS), 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 (IH). Once this occurs, SIDACtor devices reset and

    return to their high off-state impedance.

    VS (Switching Voltage) Maximum voltage prior to

    switching to on state

    VDRM (Peak Off-state Voltage) Maximum voltage that can be

    applied while maintaining off-state

    VT (On-state Voltage) Maximum voltage measured at

    rated on-state current.

    IT (On-state Current ) Maximum rated continuous on-

    state current

    IS (Switching Current ) Maximum current required to

    switch to on-state

    IH (Holding Current ) Minimum current required to

    maintain on-state

    IDRM (Leakage Current ) Maximum peak off-state current

    measured at VDRM

    SIDACtor Characteristics and Device Physics

  • 10 Confidential and Proprietary to Littelfuse, Inc. © 2007 Littelfuse, Inc. All rights reserved.

    SIDACtor Characteristics and Device Physics

    – di/dt Rate of Rise of Curren

View more >