TDK Power Electronics World. Guidebook of TDK Power Electronics Products

Transcription

1 TDK Power Electronics World Guidebook of TDK Power Electronics Products

2 Welcome to Power Electronics World Communications and broadcasting equipment Introductory Section What Is Direct Current ()? What Is Alternating Current ()? There Is No Such Thing as Perfect or 4 Why Are Stabilization Circuits Needed? 5 Power Supply Devices Play a Variety of Different Roles 6 What Is Rectification? What Is Smoothing? 7 The Functions of Main Components 8 Creating Optimal Power Supply Systems 9 Distributed Power Supply Systems and Power Modules 1 Technology Section Structure of Linear Power Supplies 11 Structure of Switching Power Supplies 12 Basic Circuits of Non-Insulation type - Converters 13 Chopper Type (Back Converter, Boost Converter), Charge Pump Type 3 Factory automation and control equipment Medical devices Measuring instruments and test equipment Computers and office automation equipment Basic Circuits of Insulation type - Converters Flyback Converter, Forward Converter, RCC Type, Push-Pull Type, Full-Bridge Type 15 Technologies for Improving Efficiency Areas of Loss in Switching Power Supplies, Soft Switching, Power Factor and Harmonic Correction (PFHC) Circuits, Synchronous Rectification Method, Digital Control Key Parts That Support Power Supply Performance Capacitors, Coils and Transformers Noise Countermeasures in Switching Power Supplies 2 Uninterruptible Power Supplies 21 New Power Supply Systems and Batteries 22 Switching Power Supply Development History Automobiles and traffic control equipment Household appliances and consumer electronics 1 2

3 Introductory Section What Is Direct Current ()? What Is Alternating Current ()? Electric current can be direct current () or alternating current (). Direct current such as the power from dry cells is characterized by a uniform direction of flow and amount () of electricity. Alternating current is characterized by direction of flow and amount of electricity that changes cyclically over time. Long ago, static electricity was the only type of electricity known, but when batteries were invented, it became possible to use electricity. Generators were later invented, and it became possible to use as well. Direct Current Current Direct current has uniform direction of flow and amount () of electricity. Primary Batteries and Secondary Batteries The symbols used in Lithium-ion diagrams for batteries battery and power supplies Lead storage cell Time Dry cell Nicad battery Button battery Batteries that are used up such as dry cells are primary batteries. Batteries that can be recharged and used repeatedly are secondary batteries (rechargeable batteries). There Is No Such Thing as Perfect or When the power of a battery (dry cell or rechargeable) falls, electric and electronic devices stop working. This is because the of a battery falls over time. In recent years, the driving of integrated circuits has declined, so even small changes in are a problem. The commercial from outlets is not stable. Commercial can become unstable depending on the load (electrical devices and so on) connected to the distribution network. For example, when all the houses in a neighborhood are using the air conditioning during the afternoon in the middle of the summer, the drops. There are also momentary stoppages in distribution and distortion to wave forms caused by the addition of noise. Cases of instability in commercial Commercial is not stable as a result of a variety of causes. Voltage The of a battery falls steadily. The discharge curves vary depending on the type of battery. Decreasing battery Time When high-frequency is added in the form of noise, the waveform can become jagged like this. Alternating Current Current Alternating current has direction of flow and amount () of electricity that change cyclically. The symbol used in diagrams for power supplies Time The direction of the electric current that comes from the two holes of the electric socket alternates. Frequency How many times the direction of changes each second is called the frequency. The unit of frequency is Hertz (Hz).The frequency of commercial is 5 Hz in eastern Japan and 6 Hz in western Japan. Voltage drop Power outage Distorted waveform The flow of electricity from generation to distribution Large plants, railways, etc. Things that are connected to power supplies and consume energy are referred to asloads.specifically, loads include resistors, circuits, connection devices, and so on. Large buildings, medium-size plants, etc. 1 cycle The waveform of the commercial power supplied by electric power companies is called a sine wave. * Not all electric power has a sine wave. There is also with a pulse waveform. Socket plug Low Frequency and High Frequency with a relatively low frequency is referred to as low frequency, and that with a high frequency is referred to as high frequency, but generally, high frequency means with a frequency in the kilo-hertz, mega-hertz, or higher range. Power plant Ultra-high (thermal, hydroelectric, nuclear, etc.) substation The difference between and is fundamental knowledge concerning 3 can easily be converted to a different using a. power electronics. 4 distribution Several hundred thousand V - 1 million V or more When electricity is distributed at high, the electric power losses (thermal losses resulting from the resistance of the power lines) are lower. Primary substation 6, V - 15, V Distribution substations 6,V 1V - 2V Transformers on utility poles Homes has the advantage of being easy to change to a different using a ( distribution is used for some portions of the distribution route).

4 Introductory Section Why Are Stabilization Circuits Needed? Power Supply Devices Play a Variety of Different Roles The from a battery or converted from commercial using an adaptor still has unstable variations in. Changes in can cause sensitive electronic devices to malfunction, so stabilization circuits are used to create with stable. Two methods of doing this are the linear method (also called the series method and dropper method) and switching method. Linear Method (Series Method) Linear Power Supply Input Voltage variation Switching Method If the circuit shown to the right is used and the switch is turned ON and quickly, the brightness of the lamp will decrease as if the dropped. Switching power supplies achieve this effect using semiconductor elements. ON Input Pulse width This is called pulse width modulation (PWM). Output The pulse width is changed according to the variation in. The current is pulsed at high frequency by switching (ON/) a semiconductor element and is sent to a that changes the. The cut portion of the electric power is lost. The linear method cuts the unevenness (variation in ) to make the smooth. Electric power converted to thermal energy and discarded using semiconductor resistors Stabilized The idea behind a switching power supply Output Voltage (V) ON Switching cycle The pulses are controlled so the area of each is the same, producing stable current with uniform. The same effect Smooth as reducing power the. The switching method uses a cutand-paste like method to produce stable current without losses, making it extremely efficient. Stabilized Most electronic devices operate on direct current. After commercial is rectified (the is still unstable), a - is used to change the power (change the or current) and stabilization circuits are used to produce extremely stable. Power Conversion Devices Inside Electronic Equipment rectification and smoothing circuits Power supply unit Electronic equipment uses a wide variety of power supply devices. - power supply devices Unstable Voltage and current conversion - Devices that convert direct currents to alternating currents are called 5 Unstable can cause electronic devices to malfunction. inverters. 6 Commercial power supply Linear Power Supplies / / The switching format is the most commonly used, so such power supplies are called switching power supplies. Switching power supplies are used as power supply units in desktop PCs, office equipment, factory automation equipment, and many other devices. There are various types including the case type, open frame type, and circuit board type. Switching Power Supplies Efficiency Low (3%-6%) High (7%-9% or higher) Radiated heat High Low Size and weight Large and heavy Compact and lightweight Degree of stability High Ordinary Radiated noise None Noise countermeasures are necessary The different circuits of electronic equipment use different operating s, so they contain multiple - s. Stabilized Input Devices Voltage and current conversion Conversion from to - inverter Because of differences in the operating s of circuits, multiple compact - s are dispersed in the vicinity of the ICs. / High s are required to illuminate the backlights of liquid crystal televisions, so current is converted to alternating current and the is stepped up using a. The main weakness of switching power supplies is the generation of switching noise in conjunction with the high-speed switching of the semiconductor elements. As a result, EMC countermeasures (noise countermeasures) such as noise filters are essential.

5 Introductory Section What Is Rectification? What Is Smoothing? Rectification is the conversion of alternating current to direct current. Rectification is performed by a diode that allows current to flow in one direction but not in the opposite direction. Direct current that has only been rectified, however, has various changes in (ripples) lingering from the alternating current. Capacitors are used to smooth the current and make it even. The Functions of Main Components In order to understand the structure of a power supply, it is necessary to know the functions of its main components. If you become familiar with the symbols used for circuits, you will be able to decipher the basic structure of a power supply circuit. Capacitors Coil (Inductor) Transformer Resistors Electrolytic capacitor jack 1V This type of adapter and battery charger is heavy because it uses a power supply with an iron core. Fuse Transformer Coil Iron core Transformer Silicon diodes ( 4, bridge format) Silicon diodes ( 4) Electrolytic capacitor Even after rectification by the diodes and smoothing by the capacitor, the direct current is still not stable. (unstable direct current) Multilayer ceramic capacitors are the leading type of surface mounted devices. Electrolytic capacitor (the indicates the polarity) Storing large amounts of electrical charge is the role of a smoothing capacitor in a power supply. The capacitor functions like a battery that can be charged and discharged instantaneously. They also have the property of allowing alternating current to pass through. A dashed line (or solid line) shows the core. Choke and other coils have cores. Coils allow direct currents to pass through smoothly, but they act as resistors to alternating current and store electrical energy. Primary winding There are power supply s and high-frequency s. Secondary winding Electrical power on a primary side passes through a core and is sent to the secondary side. At this time, losses known as core losses (mainly thermal losses) occur, and as a result, the properties of the core material have a large impact on the efficiency of the power supply. or This symbol is used in school textbooks. Voltage conversion Rectification Smoothing Discharging Charging Ripple Diodes Transistors Collector MOSFET Drain Integrated Circuits (ICs) Pulsating current There are two types of rectification: half-wave rectification that rectifies the alternating current flowing in one direction, and full-wave rectification that rectifies the current in both directions. The circuit shown above is full-wave rectification using bridge diodes. Unstable direct current Smoothing uses the charging and discharging of high-capacity capacitors. Allows current to flow through in one direction only Diodes are elements that have the property of allowing the electric current to flow through in one direction only. They are used in rectification and other circuits. Base Emitter Gate Source Transistors are semiconductor elements that have amplification functions. They are used in power supply circuits as switching elements that turned the current ON and. A MOSFET is a field effect transistor that uses metal oxide semiconductors. An integrated circuit is made up of multiple transistors, the diodes, resistors, and other components mounted on a semiconductor board (made of silicon or other material). 7 Diodes play an important role in rectification circuits, Capacitors allow alternating current to pass through, 8 and capacitors are important for smoothing circuits. while coils prevent alternating current from passing.

6 Introductory Section Creating Optimal Power Supply Systems Distributed Power Supply Systems and Power Modules Switching power supplies (- power supplies) and - s are available in numerous different formats with various sizes, capacities, shapes, and so on. - s are broadly divided into insulation types and non-insulation types. Insulation types use s (to prevent electric shocks), while non-insulation types are more compact and do not use s. Power modules that integrate numerous components onto a single compact board are also frequently used. Non-insulation type - s are often compact SMD (surface mounted device) types. Output of such s ranges from less than 1 watt to hundreds of watts. Non-insulation type - s Insulation type - Output ranges from about 1 watt to hundreds of watts - power modules - power supplies Unit type - Non-insulation type Insulation type CD/DVD drive Output power ranges from under 1 W to 3 W and higher. There are various types including wide and multi-. Open frame type Used after insulated s to convert to the necessary to operate circuits. These s are compact and low cost. Uses a and is electrically insulated. It is difficult to make these s compact or at low cost. Commercial adapter (/ conversion) LCD CPU I/O HDD - s Notebook PCs use multiple compact - s to convert to the necessary and supply it to components. These power modules integrate an - and a -. They use conduction cooling and do not need a cooling fan. Output power is in the 5 W to 1 W range. Unit type (rack-mount type) In recent years, ICs have moved to operating at lower s and higher currents, resulting in a shift to distributed power supply systems with compact, high-efficiency - s installed in the vicinity of the ICs. Earlier Power Supply Systems Problems with Earlier Systems Insulation types - power supply 48 V, Commercial etc. Unit type, open frame type switching power supplies, etc. 48 V, etc. - power modules integrate - s, - s, PFHC (power factor and harmonic correction) functions (see page 17), and various other power supply circuits. Such power modules make possible a variety of flexible distributed power supply systems. Distributed Power Supply Systems and - Power Modules - Insulation types power supply - Integrated into a compact module - power module PFE Series, etc Distributed Power Supply System Commercial What is POL? Commercial - power supply Relay Bus Converter Insulation typesintermediate - Only one insulation type - is needed. POL (point of load) Placement of a compact - near the load (IC) Non-insulation type V 3.3 V 2.5 V, etc. 12 V, 5V, etc. Non-insulation type V, 1.5V, 1.3V,.8V, etc. 61mm Brick types and sizes 116.8mm Full brick (12.7 mm high) Using multiple insulation type - s is a problem in terms of cost and space. ICs are operating on lower s, but it is not efficient to suddenly reduce the. At higher frequencies, the wire resistance to the load and effects of inductance increase. Advantages of Distributed Power Supply Systems High-efficiency non-insulation type - s generate little heat and do not require heat sinks, and as a result, can be mounted near ICs on printed circuit boards. Halfbrick Quarter brick Power modules are standardized using units called bricks. Eighth brick Sixteenth brick Power modules are high efficiency and use conduction cooling and as a result do not need a cooling fan. This means that all power supply devices can be mounted on the same printed circuit board. Non-insulation type - s are compact onboard Point of means in the immediate vicinity of the load 9 1 power supplies. (ICs, etc.)

7 Technology Section Structure of Linear Power Supplies Even after commercial is rectified and smoothed, the that is produced is not stable (see page 7). A stabilization circuit converts this to with little variation in. Lets first examine a linear type stabilization circuit, which was once the most common type of stabilization circuit. Structure of Switching Power Supplies Non-stabilized power that has been rectified is converted to high-frequency pulses by a switching element (a transistor or MOSFET) using high-speed switching and sent to a. The is detected and compared and feedback data provided to control the pulse widths to produce stable. Switching power supplies are compact, lighter, and higher efficiency than linear power supplies, but the circuits are more complex and the high-speed switching generates noise, so noise countermeasures are essential. Linear Power Supplies Use Three-Terminal ICs power supply Power supply s are big and heavy. Non-stabilized Power Supply Unit Power supply Rectification Linear Power Supply Smoothing Stabilized Power Supply Unit Threeterminal regulators, etc. Series type stabilization circuits receive stabilized by transistors, and as a result, they generate a lot of heat and are low efficiency. Power Supply Rectification which is done in the initial phase is different from a linear power supply. Rectification and smoothing circuit Switching Transformers, choke coils, and capacitors can be miniaturized. Highfrequency s Rectification and smoothing circuit Higher frequencies allow cores to be made smaller. Ferrite and other materials with low high-frequency losses are used as the core materials. Detection Principles of series type stabilization circuits (series regulators) Variable resistor Variations in the are adjusted by a variable resistor to produce stabilized. Non-stabilized Stabilized Non-stabilized with variations Stabilization circuit using three-terminal ICs (three-terminal regulator) Three-terminal IC The three-terminal ICs play the same role as the variable resistor. Linear power supplies place resistors in series to control the current, so they are also called series power supplies. They use resistance to reduce the, so they are also called dropper and series dropper power supplies. Heat Stabilized Heat is generated, so a heat sink is needed. Threeterminal IC Heat sink IN OUT GND Current Uniform Zener diode (if current is passed through in the opposite direction, a uniform can be achieved) Three-terminal ICs are integrated circuits made from transistors, Zener diodes, and other components. They generate heat, so a heat sink is attached. Switch Transistor RectificationSmoothing Switching using semiconductor elements MOS FET The switch is turned ON and at the highs and lows of the square waveform. Principles of Switching Regulators The current is turned ON and by switching elements at set intervals, converted to a pulse wave, and sent to a. A comparison of the timing of the ON status and status (duty ratio, duty cycle) is used to control the. By controlling the duty ratio (pulse width) in relation to variations in the, the is stabilized (PWM method). The is detected and compared and feedback information provided. Pulse width modulation See page 5 for the principles of pulse width modulation (PWM). Photo coupler Switching Regulator Unit ON ON ON Switching cycle The primary and secondary sides are electrically insulated and a signal is sent. Duty ratio Time that circuit is ON Switching cycle Linear power supplies are fundamentally low efficiency and 11 The key features of switching power supplies are compact size, have high thermal losses. 12 light weight, and high efficiency.

8 Technology Section Basic Circuits of Non-Insulation Type - Converters There are various forms of non-insulation type - s also. A form known as the chopper format is a compact onboard type with power in the range of less than 1 watt to several watts. Types of chopper s include the step down back and the step up boost. Each type is suitable for configuring a compact, low-cost local power supply with a low parts count. An even more simple approach is the charge pump type which uses only capacitors but no coils or s. Example of component mounting for compact onboard - s (chopper type) Choke coil Winding Core Diodes, capacitors, control ICs, etc. Back Converter (Step Down) The choke coil takes up a relatively large area. Choke coil Coils prevent variations in current and act as resistors (according to Lenzs Law). They are called chokesbecause they choke off the electric current. Compact, onboard types with low Input > Output Switching and Operation of the Coil Current Direction of electromotive force When the switch is ON, the coil generates electromotive force in a direction that prevents current from flowing in. Switch When the switch is turned off, the coil generates electromotive force in the direction as if to maintain the current. Booster Converter (Step Up) (Connected to the control circuit) Switch Input < Output The energy stored by the choke coil is increased or boosted when the switch is, raising the. Capacitors are also known as condensers because their basic function is to store electric charge. The charge pump type makes use of this function. They are compact, simple - s that do not use any s or coils and use only capacitors to convert. The electric charge stored in the capacitor is carried by switching as if in a bucket relay to increase the. The switching element is connected in parallel; this is different from the step down. When energy flows from the to the, the choke coil accumulates energy. Switch The choke coil releases the stored energy in an attempt to maintain the current. * There is also a back boost format that combines the functions of the back and the boost. This is characterized by the ability to reverse the polarity. Low- type that uses capacitors Switching element (Connected to control circuit) Diode Choke coil Switch The coil accumulates energy. Capacitor The chopper was named this because it uses switching to chop the current and transmit it. Basic Principles of Charge Pump Type - Converters (step up type) Input V S1 C1 S3 S1 S3 Output Input Output C2 V The charged capacitors are connected in series and switching is performed to raise the. C1 2V C2 When energy flows from the to the, the choke coil accumulates energy. Switch The choke coil generates electromotive force in an attempt to maintain the current and current flows through the diode to the (the switching element is connected in series with the circuit; the needed can be reduced by setting the duty cycle). S2 S4 S1 and S4 are turned ON and C1 is charged (actual switching is performed through IC operation). S2 S4 When S1 and S4 are and S2 and S3 are ON, the charge in C1 is carried to C2 and the has twice the. 13 The choke coil plays an important role in chopper type s. Coils and capacitors have the ability to store energy. 14

9 Technology Section Basic Circuits of Insulation Type - Converters Insulation type - s actively use s and support high power. Understanding the basic principles and core circuits will deepen your understanding. Principles of Transformers and Direction of Electromotive Force Symbol indicating the beginning of the windings of the primary winding Reverse electromotive force Switch (Connected to control circuit) Switch Core Reverse electromotive force (Connected to control circuit) Magnetic flux from the primary winding Reverse effect magnetic flux from the secondary winding Inductive electromotive force Symbol indicating the beginning of the windings of the secondary winding Transformer The core stores energy, so no choke coil is needed. D1 Inductive electromotive force D2 Choke coil Current When the switch is ON, magnetic flux is generated by the primary winding, but electromotive force (reverse electromotive force) is generated to prevent the magnetic flux from doubling. The magnetic flux from the primary winding passes through the core and reverse effect magnetic flux from the secondary winding is generated, creating electromotive force (inductive electromotive force) and current (inductive current) flows. When the switch is, the current flows in the opposite direction. The direction of the electromotive force from the primary and secondary windings (reverse electromotive force and inductive electromotive force) is towards the gray circle ( ). Low and Medium Output Power Types When the switch is ON, current flows in the primary winding () and the core is magnetized from the generated magnetic flux (energy storage). The direction of the diode is reversed, so no inductive current flows through the secondary winding. When the switch is, the energy accumulated in the core is released and current flows through the diode (). The coil plays a role similar to that of the choke coil. Medium Output Power Type When the switch is ON, electromotive force (reverse electromotive force and inductive electromotive force) is generated in the primary and secondary windings as a result of the principle and current flows through the diode (D1) (). At this time, energy is stored in the choke coil. When the switch is, the choke coil generates electromotive force, preventing changes in the current, the stored energy is released, and current flows through the reverse flow diode (D2) (). RCC Type (self-exciting flyback ) Low Output Power Types Q1 Q2 Q1 Push-Pull Type When Q1 is ON: When Q1 is : Base winding *A gap is placed in the core to prevent magnetic saturation (See page 19). *RCC : Ringing Choke Converter Medium to High Output Power Types When Q1 is ON: When Q2 is ON: Q1 and Q2 are switched in alternation. Push-pull types are commonly used as power supplies up to about 3 W. Full-Bridge Type Medium to High Output Power Types Q1 Q2 Q3 Q4 When Q1 is ON as a result of the base current from the base winding, collector current flows. When the base current is insufficient and Q1 is, current flows on the secondary side. The is a self-exciting type that performs this operation repeatedly. It requires only a small number of components and can be used as a simple, low power power supply. Medium to high power types use multiple switching devices which makes the circuit configuration more complex but enables higher efficiency, lower noise, and advanced functionality. Used as high-efficiency, high power power supplies with s of several hundred watts and higher. The half-bridge type replaces Q1 and Q2 with two capacitors. When Q2 and Q3 are ON: When Q1 and Q4 are ON: ON/ON Types and ON/ Types - s are available in ON/ON types that energy when the switching elements are on and ON/ types that energy when the switching elements are off. Types by Output Voltage and Power ON/ON Types (Multi-switching types: Push-pull, half-bridge, full-bridge, etc.) Output (V) ON/ Types (RCC, flyback, etc.) Power (W) ON/ Types & ON/ON Types (single-switching forward, etc.) B-H Curves of Magnetic Cores B: Magnetic flux density Saturation magnetic flux density Excitation Process The greater the magnetic permeability, the greater the slope. Magnetic permeability H: Magnetic field The narrower the curve, the smaller the losses. Comparison of Performance of Core Types Silicon Ferrite Amorphous Magnetic permeability Acceptable Good Excellent Saturation magnetization Excellent Acceptable Acceptable Iron losses Poor Excellent Excellent Manufacturing cost Acceptable Excellent Poor Iron cores generate high losses (thermal losses) at high frequencies, 15 The is the key component of insulation type - s. so they are not used. 16

10 Technology Section Technologies for Improving Efficiency If the efficiency of power supplies could be increased by just one percent, this would have a tremendous energy-saving impact on society as a whole. Some new technologies for improving energy efficiency are discussed below. The properties of the core material have a major impact on efficiency. Using accumulated ferrite technologies is one of TDKs strengths. Main areas of loss (thermal losses) in - switching power supplies Rectification and smoothing circuits Bridge diode Switching unit Control Circuit High-frequency Smoothing capacitor Transistor MOSFET High-frequency The losses of semiconductor elements are large, so various circuits have been proposed. IC High-frequency rectification circuit Rectification Smoothing diode capacitor IC Comparison and detection circuit The orange indicates the main components that generate losses (thermal losses) When multiple losses of less than 1% to several percent are combined, total losses can reach 2%. In the switching power supplies, the semiconductor elements in particular generate high losses. Also, the power supplies are compact, and as a result if the frequency of the switching operation is increased, losses also increase. Research to solve these problems is being conducted on the frontlines of power supply technology. Example of a Simple Synchronous Rectification Circuit for an Insulation Type - Converter Conventional Flyback Converter Losses from the resistance of the diode are high. High-frequency Diode Synchronous Rectification Type Flyback Converter Voltage induced by a supplementary winding drives the Q2 gate. High-frequency Supplementary winding Power MOSFET (Q2) A low resistance power MOSFET is used in place of a diode. The linkage between Q1 and Q2 (synchronous rectification) increases efficiency. Normal switching (hard switching) Voltage waveform Current waveform Turn-off time ON The areas of overlap are switching losses ( current). ON Efficiency and Power Factor of a Power Supply Efficiency = Output power (W) / Input power (W) Power factor = Effective power (W) / Apparent power (VA) Voltage waveform Current waveform This technology improves the power factor by rectifying the waveform through control of the high-frequency portions of commercial (the portions that are integral multiples of the base frequency). Soft Switching ON The areas of overlap are reduced and dead times created to reduce switching losses. A coil and capacitor store energy in the power supply and return it to the side, so the power factor is less than one. Soft switching is an advanced technology that precisely controls the timing of the ON and switching to reduce switching losses. There is the zero switching (ZVS) method, which performs switching with the at zero, and the zero current switching (ZCS) method, which performs switching with the current at zero. In response to the use of higher frequencies, a technology known as resonant power supply that uses the resonance of a coil and a capacitor to perform switching is also starting to be applied in practical applications. A power module that integrates an - with PFHC and a - PFE Series (The apparent power is the product of the values obtained from a voltmeter and an ammeter. It is the power that appears to be present.) (Connected to control circuit) Power transistor Digital control of power supplies began in communications fields and is progressing towards full digital control including control circuits. Benefits of full digital control Power supply information such as the and, current, and temperature can be displayed on a PC in real time. Energy savings are possible through precise control of the. A soft start function to prevent damage to semiconductor elements from inrush current is possible. POL power management for the distributed placement of multiple - s is beneficial. The number of components can be reduced. * In 25, we launched full digital control - s with DSP (Digital Signal Processing). Currently, - power supplies using digital control are being developed for market introduction in the near future. (Connected to control circuit) Power MOSFET (Q1) Example of a - circuit block using digital control for communications functions Communications The adoption of digital control makes possible incorporation of multiple and advanced functions in power supplies. Example of a - circuit block using full digital control Two power MOSFETs regulate the flow of current. Communications functions are controlled digitally to enhance functionality. Communications Digital interface Full Digital Control Digital interface Switching circuit Analog controller Oscillator Smoothing circuit Error amplifier Standard PWM uses analog control Switching circuit DSP (digital signal processor) Smoothing circuit Analog control units are replaced by A-D s and DSP. A-D Standard 17 The high-frequency portion of commercial reduces the power factor. Power supplies are making the transition from analog control to digital 18 control.

11 Technology Section Key Parts That Support Power Supply Performance Switching power supplies contain semiconductor elements such as diodes, transistors, MOSFETs, and ICs, while passive components such as capacitors, coils, and s also play important roles. Multilayer ceramic chip capacitors are compact and offer high reliability and long life spans. There are also high capacity types that encroach on the territories of film capacitors and electrolytic capacitors. Multilayer ceramic chip capacitors are important as EMC countermeasure components (noise countermeasure components). Switching power supplies use numerous s other than the main as well as coils. Mobile phones and other devices use SMD (surface mounted device) type compact power coils. The characteristics of the core material have a substantial impact on making power supplies more efficient as well as making them smaller, slimmer, and lighter. Choke Coils Winding wire Core Core gap Common mode choke coil Magnetic flux leakage Since the capacity is high, capacitors are used for smoothing. Aluminum electrolytic capacitors A gap is placed in the core to prevent magnetic saturation. Examples of choke coil cores (toroidal cores) Input EMC filter Switching power supplies use numerous s and coils. The magnetic flux leaking from the gap can cause noise, so shielding must be used. Active filter choke coil PFHC circuit Supplementary power supply circuit Supplementary power supply EI Core The characteristics can be controlled by adjusting the gap. Magnetic shielding is needed as a countermeasure against the magnetic flux leaking from the gap. Main Smoothing choke coil Output rectification and smoothing circuit Power switch circuit Switching element drive Such capacitors are characterized by their compact size, high reliability, and longer life spans. They also have excellent highfrequency characteristics. Multilayer ceramic chip capacitor Transformers Control Circuit Current Core gap Magnetic flux leakage EE Core The effects from magnetic flux leakage can be minimized by creating a gap in the center pole. Winding bobbins, exteriors, and ferrite cores (various types including EE cores and EI cores) Noise Countermeasures in Switching Power Supplies One of the weak points of switching power supplies is the generation of electromagnetic noise. TDK provides total EMC solutions that support all aspects of noise control from to and include various EMC countermeasure components (noise countermeasure components) and noise measurement in anechoic chambers. Noise Unique to Switching Power Supplies ( ) Switching frequency Commercial frequency Ideal Output waveform of an - switching power supply Examples of EMC countermeasures for switching power supplies ( ) Input Power Supply EMC Filters EMC Filters for Power Line Other Sources of Noise The operation of capacitors and resistors can control the switching noise and spike noise of transistors and diodes. They prevent common mode and differential mode noise and prevent it from flowing in and out. CR snubber Control circuit Flexield Comparison and detection circuit Noise generated by transistors and diodes is also radiated from heat sinks designed to release thermal energy. Magnetic flux leakage from s and choke coils can cause eddy current in metal cases, generating noise. Wires and components where large currents are turned ON and. The inductor portion of wire leads can also have an impact, so wiring and leads are made as short as possible. Voltage Voltage Wire loops become antennas and radiate noise, so the area of such loops must be minimized. A flexible electromagnetic shield material that absorbs radiated noise, converts it to heat, and eliminates it. Ferrite Cores Clamp Filters Ferrite absorbs noise to control radiated noise. Common mode filter A common mode filter on the line prevents noise from flowing out. Ripple noise Spike noise Advanced circuit design and simulation technologies are needed. High-capacity multilayer ceramic chip capacitors are also used 19 TDK provides Total EMC Solutions. for smoothing. 2

12 Technology Section Uninterruptible Power Supplies Uninterruptible power supplies (UPS) are used to prevent unforseen information system downtime caused by various interruptions to power supplies such as power outages, drops in s, and distortions to commercial waveforms. There are many types of UPS available depending on the application. Main Power Supply Methods of UPS Standard commercial type (square wave ) Line interactive type (sine wave ) Standard inverter type (sine wave ; connection is instantaneous, so there is no interruption of the wave form) Power supply interruption types and TDK-Lambda UPS categories Commercial power supply noise Variations in frequency Switching noise Voltage drops Over Power outage Select the UPS that is optimal for the power supply interruption types and the necessary capacity. Voltage sags Method of Calculating UPS Capacity Total capacity (VA) Total capacity (W) Surges Total capacity of indicated VA of device Total capacity of indicated VA of device Power factor* High-frequency distortion Rectifier (/ conversion) Level 9 Battery Power Supply Structure Using the Standard Inverter Method Total capacity of indicated W of device /.6 Total capacity of indicated W of device Inverter (/ conversion) If V and A are indicated, multiply them (e.g., 1 V & 1.8 A --> 18 VA) * Power factors will vary depending on the device. They are generally in the range of.6 to.8. Mobile type with casters Floor mount type Standard inverter type Rack mount type Capacity: Level 5 Several hundred watts to about 1 watts Line interactive type Compact, lightweight types Capacity: Level 3 Several dozen watts to several hundred watts Standard commercial power supply type The levels according to the number of power supply interruptions that the UPS can protect against and the corresponding power supply formats. During normal operation During power outage 1% to 3% additional capacity is added on top of total capacity (VA) and total capacity (W) Power outage Output of a high-quality sine wave with no distortion or noise UPS operates Select a UPS with a capacity larger than both of the calculated figures. It is necessary to have extra margin during a power outage. High-capacity installed type Installed type New Power Supply Systems and Batteries Recently, UPS batteries have been changing from conventional lead storage cells to lithium-ion batteries, and UPS units are rapidly becoming smaller and lighter and have longer life spans. Batteries will also be the key to the proliferation of electric automobiles such as hybrid electric vehicles (HEV). Energy Density of Secondary Batteries Volume energy density (Wh/R) 3 2 Nickelhydrogen battery Lithium-ion battery 1 NiCd battery Mass energy density (Wh/kg) Electronic devices operate on, and there is the idea of supplying offices and homes with as well. Energy from wind and solar power is initially stored in lithium-ion batteries. Plug-in hybrids that can be charged from a regular outlet are also appearing on the market. Saving on batteries requires highefficiency onboard - s. distribution / conversion Basic Mechanism of an HEV (using a parallel format as an example) and - Converter Power plants and substations Wind power and mini-wind power generation Power router Lights, windshield wipers, etc. Supplementary battery - High- battery Engine Generator Motor Lithium-ion batteries, nickel hydrogen batteries, and so on are stacked. High of 2 V to 3 V is achieved. TDKs HEV -. It converts high from the main battery to low. Future Model for Power Electronics distribution distribution Plug-in electric vehicles Fuel cells Inverter for the motor, generator, air conditioner Control board Highcapacity battery Solar power generation Household devices Power electronics will play a major role in saving energy and 21 A UPS comprises a rectifier, battery, and inverter. protecting the global environment. 22

13 Switching Power Supply Development History About 196 About 1965 About Stabilized power supplies using vacuum tubes were common at this time. America s NASA began developing switching power supplies for use in space craft. Development of semiconductor elements for switching power supplies begins. TDK and Nippon Electronic Memory Industry Co. Ltd. (predecessor to Nemic-Lambda) enter the switching power supply business. Nippon Electronic Memory Industry Co. Ltd. manufactures and markets Japan s first standard switching power supply. TDK manufactures and markets switching power supplies. Switching power supplies are adopted for use in commercial television games and the switching power supply market expands. TDK manufactures and markets switching power supply s. Nemic -Lambda (predecessor to Densei-Lambda) founded, to take over operations of Nippon Electronic Memory Industry Co. Ltd. TDK begins production of - s for use in HEVs. TDK launches the RKW and JBW series of switching power supplies. Densei-Lambda (the predecessor to TDK-Lambda) launches the HWS series of switching power supplies. Densei-Lambda joins the TDK Group. Sales of UPS with lithium-ion batteries (lead-free) begin. Sales of TDK-Lambda brand products begin. TDK and Densei-Lambda market a total of 234 types of EMC filters for power line in 13 series. All models available on the market comply with the RoHS Directive. TDK-Lambda Corporation launched. Advances in Switching Power Supplies (unit type, 15 W comparison) Power supplies have undergone amazing miniaturization. Japan s first standard switching power supply. 45cm 3 First generation 38cm 3 Second generation 13cm 3 12cm 3 Third generation Compliance with global standards Fourth generation 55cm 3 Compliance with EMC regulations, CE marks, etc. Fifth generation About Next generation Further miniaturization and higher efficiency Compliance with environmental regulations such as the RoHS Directive Date of publication: March 31, 29 Publisher: TDK Corporation Corporate Communications Dept Nihonbashi, Chuo-ku, Tokyo Telephone: SGS-COC-438 Cert no.