Littelfuse, Inc. · NASDAQ:LFUS
Littelfuse — Technical Presentation (2007)
40 slides from Littelfuse's technical presentation, 2007
Slide 1: Training Agenda
General Electronics Thyristor Training Training Agenda 1. Thyristor Definition and General Electronics Power Applications 2. Thyristor Characteristics and Device Physics 3. Thyristor General Electronics Applications Examples 4. Thyristor Product Selection 5. Littelfuse Thyristor Product Road Map 6.
Slide 2: Section 1: Thyristor Definition and General Electronics Power Applications
General Electronics Thyristor Training Section 1 Thyristor Definition and General Electronics Power Applications • Thyristor Definition – A semiconductor switch whose bi-stable action depends upon P-N-P-N regenerative action • Thyristor Technology for Power Applications in the General Electronics Se
Slide 3: Thyristor Definition and General Electronics
Thyristor Definition and General Electronics Thyristor Definition – A semiconductor switch whose bi-stable action depends upon P-N-P-N regenerative action. – Littelfuse devices included in the Thyristor family: Device Name Description Feature Function SCR Rectifier with control gate One Way Switch P
Slide 4: Thyristor Technology in the General Electronics Segment
Thyristor Definition and General Electronics Thyristor Technology in the General Electronics Segment – Phase Control • In these applications, thyristors are used to control the magnitude of average voltage or energy being delivered to a load. • Due to high-volume production techniques, thyristors ar
Slide 5: Thyristor Standards
Thyristor Definition and General Electronics Thyristor Standards IEC 60092-304 {Ed.3.0} Electrical installations in ships. Part 304: Equipment - Semiconductor convertors IEC 60700-1 {Ed.1.1} Thyristor valves for high voltage direct current (HVDC) power transmission - Part 1: Electrical testing IEC 6
Slide 6: Section 2: Thyristor Characteristics and Device Physics
General Electronics Thyristor Training Section 2 Thyristor Characteristics and Device Physics – Ratings, Specifications, and Characteristics • Electrical characteristics – Main terminal characteristics – Thyristor turn-on mechanisms – Gate characteristics – Current holding and latching – Turn-on and
Slide 7: Electrical Thyristor Characteristics
Thyristor Characteristics and Device Physics Electrical Thyristor Characteristics Anode-to-Cathode Characteristics – Forward characteristics: • Blocking state • Avalanche region • Breakover point • Negative resistance region • Conducting state • Holding current point – Reverse characteristics: • Blo
Slide 8: Gate Characteristics
Thyristor Characteristics and Device Physics Electrical Thyristor Characteristics Gate Characteristics A Thyristor can be gated or triggered to the ON state by applying a small signal between the gate and the cathode. The trigger source is a DC voltage and the gate current must be limited by a serie
Slide 9: Thyristor Switching Methods
Thyristor Characteristics and Device Physics Thyristor Switching Methods 1. Applying proper gate signal 2. Exceeding thyristor static dv/dt characteristics 3. Exceeding voltage breakover point Application of Gate Signal Gate signal must exceed IGT and VGT requirements of the thyristor used. For an S
Slide 10: Current Holding and Latching
Thyristor Characteristics and Device Physics Electrical Thyristor Characteristics Current Holding and Latching Latching Current (IL) is the minimum principle current required to maintain the thyristor in the on state immediately after the switching from off state to on state has occurred and the tri
Slide 11: Turn-on Time and Turn-off Time
Thyristor Characteristics and Device Physics Electrical Thyristor Characteristics Turn-on Time Turn-off Time tgt is the time interval between the tq (the circuit commutated turn off time) is the application of a gate pulse and the on-state time during which the circuit provides reverse current reach
Slide 12: di/dt and dv/dt
Thyristor Characteristics and Device Physics Electrical Thyristor Characteristics di/dt (Rate of Rise of Current) The di/dt rating specifies the maximum rate-of-rise of current through a thyristor device during turn-on. The value of principal voltage prior to turn-on and the magnitude and rise time
Slide 13: Maximum Ratings: Peak Surge On-state Current
Thyristor Characteristics and Device Physics Maximum Ratings Peak Surge On-state Current The Peak Surge current (ITSM)is the maximum peak current that may be applied to the device for one full cycle of conduction without device degradation. The maximum peak current is usually specified as sinusoidal
Slide 14: Thermal Characteristic
Thyristor Characteristics and Device Physics Thermal Characteristic Thermal Resistance VGT, IGT, IH and other key parameters of Thyristors are a function of temperature. The heat generated within the semi-conducting material must be dissipated into a heat sink. The thermal resistance defines the ste
Slide 15: SCR Construction
Thyristor Characteristics and Device Physics SCR Construction Cross section of the SCR chip and illustrations of current flow and junction biasing in both the blocking and triggered (forward biased or on-state) modes Confidential and Proprietary to Littelfuse, Inc. © 2007 Littelfuse, Inc. All rights
Slide 16: Triac Construction
Thyristor Characteristics and Device Physics Triac Construction Simplified cross-sectional views of a triac chip in various gating quadrants and blocking modes Confidential and Proprietary to Littelfuse, Inc. © 2007 Littelfuse, Inc. All rights reserved. 16
Slide 17: Sidac Construction
Thyristor Characteristics and Device Physics Sidac Construction The Sidac is a multi-layer silicon semiconductor switch. The Sidac operates as a bidirectional switch activated by voltage. In the off state, the Sidac exhibits leakage currents (IDRM) less than 5 µA. As applied voltage exceeds the sida
Slide 18: Diac Construction
Thyristor Characteristics and Device Physics Diac Construction The construction of a diac is similar to an open base transistor . The bidirectional transistor like structure exhibits a high impedance blocking state up to a voltage breakover point VBO) above which the device enters a negative resista
Slide 19: Section 3: Thyristor General Electronics Power Applications Examples
General Electronics Thyristor Training Section 3 Thyristor General Elec Power Applications Examples – SCR Application Example – TRIAC Application Example – Diac Application Example – Sidac Application Example – Littelfuse Global Lab Application Testing Confidential and Proprietary to Littelfuse, Inc
Slide 20: Applications Examples: Basic Thyristor Phase Control Unit
Thyristor General Electronics Applications Examples Basic Thyristor Phase Control Unit SCR Applications Diac Applications Triac Applications - GFCI - Inexpensive timing - Variable level lighting - Smoke detector switch for phase control control - Security alarm - Variable light output - On/Off solid
Slide 21: SCR Example: Small Gas Engine Circuit
Thyristor General Electronics Applications Examples SCR Example Flywheel, HV Xfmr Rotating magnet D1 R1 N C1 Charging Winding S S-SCR Spark Plug R2 Trigger Winding Small Gas Engine Circuit Confidential and Proprietary to Littelfuse, Inc. © 2007 Littelfuse, Inc. All rights reserved. 21
Slide 22: SCR and Rectifier Combination Controls
Thyristor General Electronics Applications Examples SCR and Rectifier Combination Controls Motor Control Confidential and Proprietary to Littelfuse, Inc. © 2007 Littelfuse, Inc. All rights reserved. 22
Slide 23: Triac Example
Thyristor General Electronics Applications Examples Triac Example Isolated Solid State Switch or Relay Confidential and Proprietary to Littelfuse, Inc. © 2007 Littelfuse, Inc. All rights reserved. 23
Slide 24: Diac Example
Thyristor General Electronics Applications Examples Diac Example Full Wave DC Motor Control Confidential and Proprietary to Littelfuse, Inc. © 2007 Littelfuse, Inc. All rights reserved. 24
Slide 25: Sidac Example
Thyristor General Electronics Applications Examples Sidac Example Gas Ignition Circuit Confidential and Proprietary to Littelfuse, Inc. © 2007 Littelfuse, Inc. All rights reserved. 25
Slide 26: Global Lab Capabilities
Thyristor General Electronics Applications 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 T
Slide 27: Section 4: Thyristor General Electronics Product Selection
General Electronics Thyristor Training Section 4 Thyristor General Elec Product Selection – Basic Power Circuit Theory • Phase Control – Selection Guide • SCR Notes • Triac Notes • Sidac Notes • Diac Notes Confidential and Proprietary to Littelfuse, Inc. © 2007 Littelfuse, Inc. All rights reserved.
Slide 28: Phase Control Application
Thyristor General Electronics Product Selection Phase Control Application Operation Method 1. The thyristor is held in the off condition 2. The thyristor is triggered into an "on" condition by the control circuitry Confidential and Proprietary to Littelfuse, Inc. © 2007 Littelfuse, Inc. All rights r
Slide 29: SCR Gating: Static Switching
Thyristor General Electronics Product Selection SCR Gating: Static Switching Use a constant or varying DC signal to turn on the SCR Gate signal can be derived from power source or an independent source • A small gate current can be used to control a large load current •SCR used as solid state relay
Slide 30: SCR Gating: AC Static Switching
Thyristor General Electronics Product Selection SCR Gating: AC Static Switching Operation Method (normally open) Operation Method 1. Permits low current switching 1. Allow SCR conduction angle less that 90° 2. SCR firing angle from 0 to 90° 2. SCR firing angle anywhere from 0 – 180° 3. R2 eliminated
Slide 31: SCR Gating: Zero Crossing Switching
Thyristor General Electronics Product Selection SCR Gating: Zero Crossing Switching Operation Method 1. SCR only fires at 0° of the half cycle, the SCR remains conducting. 2. Special zero crossing detector circuits are used to determine the instant when the ac line voltage is zero 3. Used primarily
Slide 32: SCR Gating Requirement
Thyristor General Electronics Product Selection SCR Gating Requirement SCR vs. Sensitive SCR RGK Value Considerations Sensitive Gate SCR Lower values of RGK further improves requires an RGK of about 1K ohms blocking and leakage, improves dV/dt, (typical), triggers with microAmps of increases holding
Slide 33: Triac Snubber Circuits Considerations
Thyristor General Electronics Product Selection Triac Snubber Circuits Considerations Definition: A snubber is a simple electrical circuit used to suppress ("snub") electrical transients. Operation Method 1. A series resistor and capacitor connected across main terminals of the triac 2. Resistor dis
Slide 34: Triac Commutation Considerations
Thyristor General Electronics Product Selection Triac Commutation Considerations Operation Method 1. For each AC cycle, the triac turns on twice, it must turned off before it can be turned on in the opposite direction. 2. For turn off, the load current must drop below the holding current (I H). 3. F
Slide 35: Triac Phase Control
Thyristor General Electronics Product Selection Triac Phase Control Operation Method 1. A Sensitive Gate Triac can be phase controlled from pulsed DC unidirectional inputs as shown. 2. A microprocessor can be interfaced to an AC load by using a sensitive gate triac to control a lamp's intensity or a
Slide 36: Triac Device Gating Requirement
Thyristor General Electronics Product Selection Triac Device Gating Requirement Device Type Key Advantages/Disadvantages Snubber Network Sensitive Triac Can be triggered in any two of Normally should have snubbing four modes and has IGT max spec due to lowest gate current for each mode requirements
Slide 37: Diac Device Application Requirement
Thyristor General Electronics Product Selection Diac Device Application Requirement –Voltage range of diacs is 30 to 70V –Normally 32 to 35V is used for phase control for wider control output –Tighter voltage ranges used to minimize tolerances on output voltage of control –Higher voltage diacs are u
Slide 38: Sidac Device Application Requirement
Thyristor General Electronics Product Selection Sidac Device Application Requirement –Use a low voltage Sidac for 120VAC line or less –Use a high voltage Sidac for 240VAC line or higher –Use single pulse Sidacs for High Pressure Sodium lamp ignition where one pulse per half cycle of 50/60Hz, a 1500V
Slide 39: Littelfuse Thyristor Product Road Map
General Electronics Thyristor Training Section 5 Littelfuse Thyristor Product Road Map Power Thyristor Roadmap Q1 2006 Q2 2006 Q3 2006 Q4 2006 Q1 2007 Q2 2007 Q3 2007 Q4 2007 Triac Product Family 800V Wire Bond 0.8Amp & 1Amp Triac Phase 1 Phase 2 Phase 3 8Amp Triac Benchmark Redesign Phase 1 Phase 2
Slide 40: General Electronics Thyristor Technology Challenges
General Electronics Thyristor Training Section 6 General Electronics Thyristor Technology Challenges – Higher Current/Surge Ratings in Smaller Packages – Multiple Elements in One Package – Thyristor Isolation from Gate (Opto-Thyristor) – UL Recognition of Thyristors – Thyristor technology Packaged i