ECE101 Week 01 and 02: Semiconductor Switches PDF

ECE101 – Week 01 and 02: SEMICONDUCTOR SWITCHES DISCLAIMER Fair use of a copyrighted work as defined in sec. 185 of RA 8293, which states, “the fair use of a copyrighted work for criticism, comment, news reporting, teaching including multiple copies for classroom use, scholarship...

ECE101 – Week 01 and 02: SEMICONDUCTOR SWITCHES DISCLAIMER Fair use of a copyrighted work as defined in sec. 185 of RA 8293, which states, “the fair use of a copyrighted work for criticism, comment, news reporting, teaching including multiple copies for classroom use, scholarship, research, and similar purposes is not an infringement of copyright.” This PowerPoint Learning Material is prepared and compiled by Engr. Raymart Mallari solely for students of Pamantasan ng Cabuyao (PnC) under the College of Engineering enrolled in ECE101 for EcE course for AY 2023-24. INTENDED LEARNING OUTCOMES After this session, the students will be able to: Differentiate semiconductor switches for specific applications Describe characteristics of semiconductor switches and their role in power supply systems Explain the significance of passive components in power supply circuits SEMICONDUCTOR SWITCHES Semiconductor Switches Solid-state devices are completely made from a solid material, and their flow of charges is confined within it. The term “solid-state” is often used to show the difference between the earlier technologies of vacuum and gas- discharge tube devices and the exclusion of conventional electro- mechanical devices (relays, switches, hard drives, and other devices with moving parts). TYPES Power Diodes A power diode has a P-I-N structure as compared to the signal diode having a PN junction. Structure - P-I-N structure, allowing for high reverse voltage handling. Forward Voltage Drop - Typically around 1V. Reverse Recovery Time - Has a stored charge that leads to a reverse recovery time when switching off. Power Diodes Applications Used in rectifiers, voltage clampers, and voltage multipliers. Suitable for high-power applications due to their ability to handle large currents and voltages. MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) Control - Voltage-controlled, operates with majority carriers (unipolar). Structure - Vertical channel structure in power MOSFETs enhances power handling. Switching Speed - Fast switching capabilities, affected by gate capacitances. MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) Applications Commonly used in power amplifiers, switching power supplies, and inverters. Ideal for applications requiring high efficiency and fast switching. MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) BJT (Bipolar Junction Transistor) Structure - Three-layer, two-junction device (NPN or PNP). Performance - Lower input capacitance compared to MOSFETs, but slower response. Saturation Voltage - Lower saturation voltage over a wide temperature range. BJT (Bipolar Junction Transistor) Applications Used in high-voltage and high-current applications, although less common now due to the rise of IGBTs and MOSFETs. IGBT (Insulated Gate Bipolar Transistor) Combines the advantages of BJTs and MOSFETs. High Input Impedance - Like MOSFETs, but can handle high voltages like BJTs. Switching Speed - Moderate switching speed, slower than MOSFETs but faster than BJTs. IGBT (Insulated Gate Bipolar Transistor) Applications Widely used in inverters, motor drives, and power electronics applications requiring high efficiency. SCR (Silicon-Controlled Rectifier) Control - Can only be turned on by a gate signal; does not have a gate- controlled turn-off capability. Operation - Remains in the conducting state until the anode current falls below a certain threshold (holding current). Switching Speed - Typically operates at low frequencies (around 60 Hz). SCR (Silicon-Controlled Rectifier) Applications Commonly used in AC power control, phase control, and rectification applications. GTO (Gate Turn-Off Thyristor): Control - Can be turned on by a positive gate current and turned off by a negative gate current, allowing for more flexible control. Switching Speed - Faster switching compared to SCRs, typically operating at frequencies up to 5 kHz. Voltage Drop - Generally has a higher voltage drop than SCRs during operation. GTO (Gate Turn-Off Thyristor): Applications Used in high-current and high-speed switching applications, such as inverters and chopper circuits. MCT (MOS-Controlled Thyristor) Control - Utilizes two MOSFETs for turn-on and turn-off, allowing for voltage-controlled operation. Switching Speed - Comparable to GTOs, with switching frequencies also around 5 kHz. Voltage Rating - Can handle high voltage ratings, typically up to 4.5 kV. MCT (MOS-Controlled Thyristor) Suitable for capacitor discharge applications, circuit breakers, and AC- DC or AC-AC conversion, providing a more efficient alternative to GTOs due to simpler gate drive requirements. ECE101 – Week 03 and 04: RECTIFIERS AND PHASE-CONTROLLED RECTIFIERS DISCLAIMER Fair use of a copyrighted work as defined in sec. 185 of RA 8293, which states, “the fair use of a copyrighted work for criticism, comment, news reporting, teaching including multiple copies for classroom use, scholarship, research, and similar purposes is not an infringement of copyright.” This PowerPoint Learning Material is prepared and compiled by Engr. Raymart Mallari solely for students of Pamantasan ng Cabuyao (PnC) under the College of Engineering enrolled in ECE101 for EcE course for AY 2023-24. INTENDED LEARNING OUTCOMES After this session, the students will be able to: Determine ripple voltage impact on DC output quality Describe phase control's role in output voltage regulation Assess bridge rectifier efficiency and its effect on output ripple DISCUSSION Introduction A rectifier is an electronic device that converts alternating current (AC) to direct current (DC) by allowing current to flow in only one direction. Introduction Rectifiers are classified into two main types: Uncontrolled Rectifiers: These rectifiers have a fixed output voltage that cannot be controlled. They are further divided into half-wave and full-wave rectifiers. Controlled Rectifiers: These rectifiers have an adjustable output voltage that can be controlled. They use devices like SCRs, MOSFETs, or IGBTs to control the output. Controlled rectifiers are also classified as half-wave or full-wave. Introduction Rectifiers are classified into two main types: Uncontrolled Rectifiers: These rectifiers have a fixed output voltage that cannot be controlled. They are further divided into half-wave and full-wave rectifiers. Controlled Rectifiers: These rectifiers have an adjustable output voltage that can be controlled. They use devices like SCRs, MOSFETs, or IGBTs to control the output. Controlled rectifiers are also classified as half-wave or full-wave. Half-wave Rectifiers Use a single diode to convert only one half-cycle of the AC waveform to DC Output voltage is pulsating DC Efficiency is low at around 40.6% Ripple frequency is the same as the AC supply frequency Half-wave Rectifiers Full-wave Rectifiers Use two diodes or a four-diode bridge configuration to convert both half- cycles of the AC waveform to DC Output voltage is also pulsating DC but with a higher frequency Efficiency is higher at around 81.2% Ripple frequency is twice the AC supply frequency Full-wave Rectifiers Full-wave Rectifiers Filter Circuit Ripple Factor (𝜸) The ripple factor is the ratio between the RMS value of the AC voltage (on the input side) and the DC voltage (on the output side) of the rectifier. 2 𝑉𝑟𝑚𝑠 𝛾= −1 𝑉𝑑𝑐 Efficiency (η) Rectifier efficiency (η) is the ratio between the output DC power and the input AC power. 𝑃𝑑𝑐 𝜂= 𝑃𝑎𝑐 Form Factor (FF) The form factor is the ratio between RMS value and average value. 𝑅𝑀𝑆 𝑣𝑎𝑙𝑢𝑒 𝐹𝐹 = 𝐴𝑣𝑒𝑟𝑎𝑔𝑒 𝑣𝑎𝑙𝑢𝑒 Principles of Phase Control and Single- Phase Phase-Controlled Rectifiers Phase control is a technique used in controlled rectifiers to adjust the output voltage by controlling the firing angle of the SCRs. By varying the firing angle, the conduction period of the SCRs can be controlled, allowing for a variable DC output. Principles of Phase Control and Single- Phase Phase-Controlled Rectifiers ECE101 – Week 05: SWITCH-MODE POWER SUPPLY DISCLAIMER Fair use of a copyrighted work as defined in sec. 185 of RA 8293, which states, “the fair use of a copyrighted work for criticism, comment, news reporting, teaching including multiple copies for classroom use, scholarship, research, and similar purposes is not an infringement of copyright.” This PowerPoint Learning Material is prepared and compiled by Engr. Raymart Mallari solely for students of Pamantasan ng Cabuyao (PnC) under the College of Engineering enrolled in ECE101 for EcE course for AY 2023-24. INTENDED LEARNING OUTCOMES After this session, the students will be able to: Create efficient SMPS circuits considering different topologies Evaluate SMPS performance based on design considerations and efficiency optimization. Describe PWM techniques and their impact on inverter waveform quality. DISCUSSION Introduction A switch-mode power supply (SMPS) is an electronic power supply that incorporates a switching regulator to efficiently convert electrical power. It transfers power from a DC or AC source (often mains power) to a DC load, such as a personal computer, while converting voltage and current characteristics. Typical Linear Power Supply Circuit SMPS Circuit Key Parts of an SMPS 1. Input Rectifier and Filter Converts AC input voltage to DC and filters out noise and harmonics 2. High-Frequency Switching Element A semiconductor switch like a MOSFET or IGBT rapidly switches the DC on and off at high frequencies to regulate output power 3. Pulse Width Modulator (PWM) Controller Controls the switching frequency and duty cycle of the switch to regulate the output voltage and ensure stability. Key Parts of an SMPS 4. Transformer (High-Frequency Transformer) Steps up or steps down the voltage level depending on the design. High- frequency operation allows smaller transformer size compared to traditional power supplies. 5. Output Rectifier and Filter Converts the high-frequency AC from the transformer back to DC and filters it to provide a stable DC output. Key Parts of an SMPS 6. Feedback Control Circuit Monitors the output voltage and adjusts the PWM controller to maintain a constant output voltage, even with varying input voltage or load conditions. 7. Output Rectifier and Filter Includes components such as overvoltage protection (OVP), overcurrent protection (OCP), and thermal protection to safeguard the power supply and connected devices. SMPS Topologies Buck Converter Boost Converter Buck-Boost Converter Buck Converter The Buck switching regulator is a type of switch mode power supply circuit that is designed to efficiently reduce DC voltage from a higher voltage to a lower one, that is it subtracts or “Bucks” the supply voltage, thereby reducing the voltage available at the output terminals without changing the polarity. Buck Converter Boost Converter The boost converter is designed to increase a DC voltage from a lower voltage to a higher one, that is it adds too or “Boosts” the supply voltage, thereby increasing the available voltage at the output terminals without changing the polarity. Boost Converter Buck-Boost Converter The Buck-Boost switching regulator is a combination of the buck converter and the boost converter that produces an inverted (negative) output voltage which can be greater or less than the input voltage based on the duty cycle. Buck-Boost Converter Operation of each SMPS Topology Please refer to the videos attached to the week topic on our Google classroom to see operation of buck, boost, and buck- boost converters.