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Freescale Semiconductor M68HC08 manual Chapter Reference Design, Application Outline

Models: M68HC08

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Chapter 3

Chapter 3

Reference Design

3.1 Application Outline

The presented system is designed to control two parallel connected fluorescent lamps. The reference design meets the following performance specification:

•Single board solution with MC68HC908LB8 microcontroller

•Supported power supply: 110V/60Hz and 230V/50Hz

•Low THD

•High power factor achieved using the PFC circuit

•Control techniques incorporating:

–Preheating

–Strike

–Run mode

•User interface (dimming level potentiometer, monitor mode interface)

•Flickering effect removal

•Lamp aging recognition

•Fault detection

–DC-bus under-voltage detection (software)

–DC-bus over-voltage detection (software)

–Ignition fault (software)

–Zero current fault (software)

3.2 Dimmable Light Ballast Characteristics

Table 3-1provides the basic characteristics of the Dimmable Light Ballast Demo with PFC at 25°C and 400 V DC-bus voltage.

Dimmable Light Ballast with Power Factor Correction, Rev. 1

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Freescale Semiconductor M68HC08 Chapter Reference Design, Application Outline, Dimmable Light Ballast Characteristics

Contents

Designer Reference Manual M68HC08 MicrocontrollersDRM067 Rev. 1 12/2005 Page Designer Reference Manual Freescale Semiconductor Draft 2 for ReviewChapter Control Theory Contents Chapter IntroductionChapter Reference Design Chapter Hardware DesignAppendix A. Schematics and Part List Chapter Demo SetupChapter Software Design Appendix B. References1.2 Benefits of this Solution Chapter Introduction1.1 Introduction 1.3 The MC68HC908LB8 Microcontroller 7-bitkeyboard interrupt Freescale Semiconductor Introduction2.1 Introduction Chapter Control Theory2.1.1 Fluorescent Lamp Control Theory 2.1.2 Fluorescent Lamp OperationGas filling mixture Freescale Semiconductor 2.1.3 Controlling the Fluorescent LampFreescale Semiconductor 2.2.1 Introduction 2.2PFC Control TheoryFreescale Semiconductor Freescale Semiconductor Control Theory MCU PWM PWM1 FAULT PINDC Bus Voltage ZeroFigure 2-8.Generated Input Current Waveform 2.2.4 Concept SummaryFreescale Semiconductor Control Theory3.2 Dimmable Light Ballast Characteristics Chapter Reference Design3.1 Application Outline Table 3-1.Light Ballast Characteristics 3.3 Application Description3.3.1 Light Ballast Control 3.3.2 Power Factor CorrectionCONTROL BOARD MC68HC908LB83.4 Software Specification 3.5 Hardware Specification3.3.3 Protection Features Chapter Hardware Design 4.1 Hardware Implementation4.2 System Modules Hardware Design 4.2.1 Input and PFCFigure 4-3.Dimmable Light Ballast - Input and PFC Freescale Semiconductor 4.2.2 InverterSystem Modules Figure 4-4.Dimmable Light Ballast - InverterFreescale Semiconductor HALF BRIDGE4.2.3 Microcontroller System Modules SignalPin number TOP BOT Comp Comp Out Zero DetectTable 4-2.J2 Interface Header SignalHardware Design Pin number4.2.4 Power Supply Figure 4-6.Dimmable Light Ballast - Power SupplyTable 4-3.Supplied Voltages Freescale Semiconductor Hardware DesignChapter Software Design 5.1 Introduction5.2 Control Algorithm Description 5.2.1.2 Phase Shift Synchronization 5.2.1 Power Factor Correction Control5.2.1.4 Generation of Output PFC Control SIgnal 5.2.1.1 DC-busVoltage Control5.2.2 Light Ballast Control 5.2.2.1 Tube Start Mode5.2.2.2 Luminance Level Control Tube Run Mode ireq = A ⋅ ek ⋅ ireqAD + q q = itADmin - A ⋅ ek ⋅ ADminrounditmin ⋅ ADmax ⁄ imax rounditmax ⋅ ADmax ⁄ imax5.3 Software Implementation 5.3.1 Initialization Setup5.3.1.1 PWM Setup PWM Frequency = 5.3.1.2 HRP SetupBusFrequency Hz Hz5.3.2 Main Program Loop 5.3.3 Synchronization Interrupt Routine 5.3.4 Sine Wave Generation Interrupt RoutineFreescale Semiconductor Software Design Set 1ms flag and reset 1ms counterinterrupt void pwmISRvoid Read new PWM value from table * sineGain5.3.4.1 Fault Detection and Processing Figure 5-6.Flow Chart - timovISR and faultISR 5.4 Detailed Software DescriptionSoftware Design Stop HRPDetailed Software Description Figure 5-7.Flow Chart - Main Flow, PartFigure 5-8.Flow Chart - Main Flow, Part Software DesignFreescale Semiconductor Figure 5-9.Flow Chart - Main Flow, Part Detailed Software DescriptionFreescale Semiconductor Figure 5-10.Flow Chart - Main Flow, Part Software DesignFreescale Semiconductor 5.5.1.4 Timer Interface Module TIM 5.5.1.1 High Resolution PWM HRP5.5 Microcontroller Usage 5.5.1 Microcontroller Peripheral Usage5.5.3 I/O Usage 5.6 Definitions of Constants and VariablesSoftware Design I/O pin5.6.1 System Setup Definitions defines the minimum HRP frequency in kHz 5.6.2 System Constants and Variables Page 6.1 Hardware Setup Chapter Demo Setup6.2 Software Setup 6.2.1 Required Software Tools6.2.4 Project Files 6.2.3 Executing the Application\prm\P&E FCS linker.prm, linker program file \Sources\pi controller.c, PI regulators fileA.1 Schematics Appendix A. Schematics and Part ListPFC Current Sense 2.7mHComp PFC GateComp PFC Current SensePFC Gate Zero DetectDCB TOP BOT Figure A-3.InverterO1 O2 O3 O4 O5 O6 O7 O8 COM LOSerial Data TOP BOT Comp - Comp Out Zero DetectSerial Data DCB Divider Tube Current Tube Current Tube Voltage differenceSerial Data5 GNDSerial Data DCB Divider Tube Current Tube Current Tube Voltage differenceFigure A-6.Power supply DESIGNATORS A.2 Parts ListQUANTITY DESCRIPTIONQUANTITY DESIGNATORSDESCRIPTION MANUFACTURERFreescale Semiconductor Appendix B. References Freescale Semiconductor Page Home Page How to Reach UsE-mail USA/Europe or Locations Not Listed