1. SWITCH-MODE POWER SUPPLIES AND SYSTEMS Silesian University of Technology Faculty of Automatic Control, Electronics and Computer Sciences Ryszard Siurek Ph.D., El. Eng. Lecture No 1

2. Program of the course Lecture No 1-General overview of power supplies, basic func- tions, static and dynamic parameters related to the output the output Lecture No 2-protection circuits (overcurrent, overvoltage etc.), additional functions and indications, paralleling of power supplies, redundancy Lecture No 3-Input parameters specified for power supplies, Electomagnetic Noise emission, Power Factor, Immunity against electromagnetic disturbances, general overview of power supply systems Lecture No 4-Linear regulator in comparison to switching one, analysis of basic topology – step-down switching regulator, general equations and waveforms Lecture No 5-Analysis of step-up and flyback switching topolo- gies, basic equations and waveforms, problem of discontinuous current (magnetic flux) flow Lecture No 6-Switching converters, pulse power transformer, analysis of single-ended forward converter, trans- former reset circuits, transformer saturation

3. Lecture No 7-Push-pull converter analysis, transformer opera- tion explanation on hysteresis curve, core satu- ration problems, bridge an half bridge converters Lecture No 8-Single-ended flyback converter analysis, parasitic (leakage) inductance problems, multi-output power supplies Lecture No 9-Output filter components - capacitors, inductors, influence on switching regulator performance Lecture No 10-Power losses in magnetic components, skin and proximity effects Lecture No 11-Pulse transformer designing basis – flyback, for- ward and push pull converter, power losses in switching regulator, power losses reduction Lecture No 12-Regulated switching converters, closed feedback loop analysis

4. Recommended books and articles 1. Abraham I. Pressman - Switching Power Supply Design, Second Edition, McGraw-Hill, New York, 1998 McGraw-Hill, New York, 1998 2. Billings K. - Switchmode Power Supply Handbook, McGraw-Hill, New York, 1989 McGraw-Hill, New York, 1989 3. Texas Instrument - Power Supply Design Seminars (1996 to 2007), to view or download go to: to view or download go to: power.ti.com (Support/Training/Seminar Materials) power.ti.com (Support/Training/Seminar Materials) 4. Ferenczi O. - Zasilanie układów elektronicznych. Zasilacze impulsowe, WNT, Warszawa, 1989 Zasilacze impulsowe, WNT, Warszawa, 1989 5. Pałczyński B., Stefański W. - Półprzewodnikowe układy i urządzenia techniki impulsowej, WKL, Warszawa, 1973 techniki impulsowej, WKL, Warszawa, 1973

5. Basic requirements for low and medium power DC Power Supplies primary circuit secondary circuit(s) isolation barrier input/line voltage AC or DC U1 U2 Un... ~ ~ / = output DC voltages hazardous/lethal voltage area safety low voltage area (ELV or SELV) General configuration of the Power Supply -15% - +10% regulated voltages = isolated output

6. Essential functions performed by the typical Power Supply Delivering of one or several output voltages with certain load capabilities, mostly DC voltages in the range of 3V to 48V Delivering of one or several output voltages with certain load capabilities, mostly DC voltages in the range of 3V to 48V Protection against electric shock – sufficient isolation of low voltage outputs from hazardous supply/line voltage Protection against electric shock – sufficient isolation of low voltage outputs from hazardous supply/line voltage Output voltage/voltages regulation against input voltage and load changes Output voltage/voltages regulation against input voltage and load changes

7. Output voltage static (steady state) parameters  U out =  U out  T TTTT x  U out  I  I +I +I +I + x  U out  U we  U we + x Equation describing the influence of most important factors on the output voltage (1.1) Load regulation coefficient % U out IoIoIoIo (I omin – I omax ) Presented usually in technical data sheets Line regulation coefficientTemperaturecoefficient % U out  U we (U wemin – U wemax ) Presented usually in technical data sheets % U out Presented usually in technical data sheets deg

8. Ripple and noise – observed within the range of several hundreds of Hz 10ms - 100Hz U wy ms t

9. Output voltage dynamic parameters Output voltage ripple & noise 510 152025 30  U wyp-p Magnified output voltage waveforms observed within the range of several hundreds of kHz output voltage – mean value basic ripple switching ripple

10. Dynamic output voltage swing related to load current step change load current output voltage load current step change output voltage dynamic reaction output voltage static change - load regulation

11. Start-up overshoot) heavy load load low loadUout Uo t