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Intelligent Lighting & Control

Microchip Technology’s Lighting Solutions

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Intelligent Lighting and Control solutions from Microchip can meet the technical needs of lighting engineers with a large array of 8-, 16-, 32-bit PIC® microcontrollers, analog, wireless, and human interface products. With advanced peripheral integration and support for all lighting technologies, including LED and fluorescent, a scalable Microchip solution provides significant flexibility versus that of pure analog or ASIC implementation. Designing with Microchip based lighting solutions enables innovation that expands lighting product capabilities and provides product differentiation.

Lighting Controls

Irrespective of the specific lighting technology, the ability to effectively control the light source is essential. Beyond a simple on/off switch, advanced lighting control provides the opportunity to provide additional intelligence and increased energy savings.

The ability to dim any light source is the most common requirement of a light controller – but is a potential obstacle. Most legacy dimmers are simple triac dimmers that can vary the light output of an incandescent light source from 0 – 100%. In order to dim LED and fluorescent lighting, specialized methods such as varying PWM frequency or variable current is required.

A Microchip based solution can provide these capabilities and more…

Functions such as dimming and timers are common, but intelligent control provides the opportunity to provide improved user interfaces and value. Incremental energy savings can be provided by integrating elements such as energy management/harvesting (ie. solar), ambient light compensation (reducing light output based on other localized light sources), and occupancy or motion sensing.

With a Microchip based solution, these capabilities can be integrated into the luminaire ballast/driver, wall controller, or remotes.

LED Lighting Technology

LED Lighting Technology

At the forefront of the most efficient incandescent alternatives are LED and Fluorescent technologies. Both have advantages and technical challenges and provide significantly improved efficacy (lumens/watt) over incandescent lighting. Additionally both technologies provide opportunities to add intelligence beyond simple incandescent light bulb replacement.

Advantages

  • Best overall efficiency
    • ~75% less energy than incandescent
    • ~25% input energy = light
    • more than 100 lumens/watt (efficacy)
  • Long life: >50,000 hours
  • No “warm-up”
  • No radiated heat
  • Good in indoor and outdoor applications

Disadvantages

  • Near term expense
  • Requires electronic drive
  • Requires thermal solution to remove conducted heat

Unlike an incandescent or fluorescent light source, a LED does not radiate heat. Rather, the heat is conducted via the backside of the LED semiconductor material. This creates a technical obstacle as excessive heat can deteriorate LED performance, function, and overall lifetime. In order to properly remove the heat in a high power LED application, it may be necessary to utilize a thermal heat sink, active fan, or actively reduce lumen output based on temperature.

A Microchip based solution can provide these capabilities and more….

Controlling a LED

LED light output is a direct function of the current flow – too little current and the light will dim, too much current and lifetimes will be shortened. A typical LED driver is DC power supply providing converted AC or DC power directly controlling the LED via constant current, Pulse Width Modulation (PWM), or other variations. The LED driver must also provide high efficiencies and power factor correction (PFC) while protecting from AC line voltage fluctuations.

Constant Current Method

  • Light output maintained by constant current level
  • Dimming control via varying current level
  • Requires high resolution current control

Modulated Current Method

  • Fixed current drive chopped by PWM
  • Dimming control via varying PWM duty cycle

LED drivers can be designed to offer dimming and RGBW color mixing capabilities by either providing a high resolution PWM (or variants such VFM – Variable Frequency Modulation) signal or varying the constant current.

Efficient Power Conversion

Microchip based solutions can support any LED drive methodology as well as add additional capabilities beyond that of traditional lighting solutions. The flexibility of these solutions allows for simplified attachment to existing designs or the development of full Switch Mode Power Supply (SMPS) based intelligent solutions.

The input supply voltage and the LED forward voltage characteristics determine the SMPS topology that is required. The SMPS topologies utilized to regulate the power within LED lighting applications are the same used within a power supply application. Each SMPS topology has its advantages and determining the proper topology is dependent upon the specific application requirements.

Intelligent Control Capabilities

In addition to efficient power conversion and LED control, a Microchip based lighting solution provides opportunities to further enhance your lighting application through product differentiation and increased user experience.

  • Custom User Interface
    & Control
  • Communication & Networking
  • Environmental Sensing
    • Motion, External Light Source, etc.
  • Day Light Harvesting
    & Auto-Dimming
  • Thermal Management
    • Active & Passive
  • Smooth Dimming Control
  • Color Mixing
  • Closed Loop Lighting Control
  • Color & Lumen Compensation
  • System Health Monitoring
  • Predictive Failure Monitoring
  • Remote Fault Detection
  • Energy Monitoring & Control
  • Energy Harvesting
    • Solar, Radio, etc.
  • Battery Management & Charging
  • Fully Customizable Options

Fluorescent Lighting Technology

LED Lighting Technology

At the forefront of the most efficient incandescent alternatives are LED and Fluorescent technologies. Both have advantages and technical challenges and provide significantly improved efficacy (lumens/watt) over incandescent lighting. Additionally both technologies provide opportunities to add intelligence beyond simple incandescent light bulb replacement.

Advantages

  • Relatively Inexpensive
  • Good Efficiency
    • ~75% less energy than incandescent
    • ~25% input energy = light
    • More than 70++ lumens/watt (efficacy)
  • Long Life: >20,000 hours

Disadvantages

  • Requires ballast to initiate & maintain electrical reaction
  • Typically requires “warm-up”
  • Can contain mercury
  • Sensitive to environment & orientation

Variations (Gas Discharge & Arc Lamps)

  • Fluorescent, CFL, HID, Low/High Pressure Sodium,
  • Induction, Neon, Xenon, Mercury Vapor, Metal Halide

Typical fluorescent lighting operates by driving a current through a glass enclosure containing an inert gas along with mercury – and with the help of phosphors, create visible light when excited by electricity. Arc lamps are similar in function but create visible light through electrically excited gases (plasma) without the use of phosphors. Whether its gas-discharge or arc lamps – a ballast is required to initiate and maintain this electrical reaction.

A Microchip based solution can provide these capabilities and more…

Controlling a Fluorescent Source

The ballast kick-starts the electrical-gas reaction with a large amount of energy and then regulates the current back down to a normalized operating current. To accurately control this reaction as well as provide smooth dimming control – high resolution PWM frequency control is required.

Efficient Power Conversion

Microchip based solutions can provide accurate lighting and dimming control as well as add additional capabilities beyond that of traditional lighting solutions. The flexibility of these solutions allows for simplified attachment to existing designs or the development of full Switch Mode Power Supply (SMPS) based intelligent solutions.

PIC MCU attach to basic power supply

  • Simplified design-in
  • Customizable features
  • Simplified modifications via firmware updates
  • Intelligent Control Capabilities

SMPS with PIC MCU & Microchip Analog

  • Increased MCU integration
  • Fully Customizable
  • Increased Efficiency
  • Power Factor Correction (PFC)
  • Flexible Topologies
  • Simplified modifications via firmware updates
  • Closed loop control feedback
  • High performance PWM and current control variation
  • Intelligent Control Capabilities

The SMPS topologies utilized to regulate the power within lighting applications are the same used within a power supply application. Each SMPS topology has its advantages and determining the proper topology is dependent upon the specific application requirements.

Intelligent Control Capabilities

In addition to efficient power conversion and LED control, a Microchip based lighting solution provides opportunities to further enhance your lighting application through product differentiation and increased user experience.

  • Custom User Interface & Control
  • Communication & Networking
  • Environmental Sensing
    • Motion, External Light Source, etc.
  • Auto-Dimming
  • Smooth Dimming Control
  • System Health Monitoring
  • Predictive Failure Monitoring
  • Remote Fault Detection
  • Energy Monitoring & Control
  • Battery Management & Charging
  • Fully Customizable Options

Incandescent Lighting Technology

Incandescent Lighting Technology

Since Edison developed the first practical incandescent light bulbs in 1880, they have remained the primary source of illumination in a wide array of applications. As environmental concerns spark “Green” initiatives and new legislation is introduced in many countries around the world to demand reductions in energy consumption, the lighting industry is challenged to replace the incandescent light bulb with new and more efficient technologies.

Advantages

  • Cheap
  • Large amounts of visible light
  • No electronics required

Disadvantages

  • Poor Efficiency
    • ~10% input energy = light
    • ~90% input energy = radiated heat
    • 10-30 lumens/watt (efficacy)
  • Short Life: 1000 – 2000 hours

Variations

  • Halogen, metal halide

Incandescent light sources are good at creating large amounts of visible light and even greater amounts of heat. As a result, a typical light bulb is not very efficient – only about 10% of the input energy is being output as light while the remaining 90% is being wasted as radiated heat. Ranging from several hundred to a couple thousand hours, the typical light bulb has a relatively short lifetime due to the extreme heat of the tungsten filament causing it to evaporate and eventually fail.

Incandescent lighting efficiency can however be maximized via the creation of Intelligent Controls with capabilities such as; timers, environmental sensing, wired/wireless communications, and touch sensing.

Dimming Incandescent Lamps

Early dimmers were simple variable resistors in series with the lamp to adjust the light level. Varying the resistance directly affects current flow to the lamp filament – directly affecting the light output.

With the advent of semiconductor switches (rectifiers and thyristors) a new method of dimming was born. This dimming method involves delaying the turn-on time of a triac until a controlled time after each zero crossing of an AC signal. Here, the delay circuit is comprised of RC network with a variable resistance. The solution is simple, but there is still a significant amount heat dissipated in the resistor due to the high voltages involved.

A much for efficient variation utilizes a PIC® microcontroller to generate an appropriate time delay for a triac – resulting in higher efficiency and accurate dimming control. Additionally, a PIC microcontroller implementation lends itself to numerous advanced control opportunities.

Scalable, Integrated Lighting Solutions

Focus Peripheral Integration

Microchip is an industry leader by continually investing and expanding upon the PIC® microcontroller line-up. Emphasis is persistently focused on reducing costs while developing products with a strong mix of peripherals such as LCD drive, PWM, ADC, comparators, timers and communication. Beyond standard peripherals, Microchip is constantly bringing additional value to PIC microcontrollers by developing unique and exclusive peripherals. These unique peripherals allow embedded lighting engineers to simplify their designs and create ever more creative applications and products. This innovation is demonstrated by some of the following PIC microcontroller integrated peripherals.

Peripheral Summary
Peripheral Capability Product Integration
(HRPWM) High Resolution PWM High speed >17-bit PWM resolution All PIC microcontrollers with NCO & CLC
(PSMC) Programmable Switch Mode Controller Advanced, customizable high speed 16-bit PWM module PIC16F178x Family
(COG) Complementary Output Generation Enhanced non-overlapping waveform generator PIC12F752, PIC16F753
(CWG) Complementary Waveform Generation Non-overlapping waveform generator PIC10F32x Family, PIC16F150x Family
(NCO) Numerically Controlled Oscillator Industry’s most precise, linear, low-cost 20-bit PWM PIC10F32x Family, PIC16F150x Family
(CLC) Configurable Logic Cell Integrated combinational & sequential logic PIC10F32x Family, PIC16F150x Family

High Resolution PWM (HRPWM)

  • 17-bit PWM capability at high frequency
  • Utilizes Integrated NCO & CLC
  • Higher Frequency Operation
    • Reduced sizing of inductors and capacitors
  • Induced jitter with improved EMC performance
Conventional PWM versus HRPWM
Conventional PWM HRPWM
PWM Resolution 16b variable
PWM Clock Frequency 16 MHz 16MHz
Target Switching Frequency 500 kHz 500 kHz
Target Period Width 1 ÷ 500kHz = 2µs 1 ÷ 500kHz = 2µs
Best PWM Pulse Adjustment 1 ÷ 16MHz = 62.5ns 15.26ps **
Maximum # of Steps per Period 2µs ÷ 62.5ns = 32 2µs ÷ 15.26ps = 131,072
Effective Full Range PWM Resolution log2 32 = 5 bits log2 131,072 = 17 bits

Programmable Switch Mode Controller (PSMC)

  • Single 16-bit PWM with up to 6 steerable outputs
  • Complementary 16-bit PWM with up to 3 steerable output pairs
  • Clock sources: external, system clock, independent 64 MHz oscillator
  • Input sources: comparators, external pins
  • Blanking control for transient filtering
  • Independent rising/falling edge control
  • Dead band with independent rise and fall control
  • Polarity control/auto shutdown and restart
  • Flexible PWM output modes
  • Burst Mode – externally control activate/deactivate

Complementary Waveform Generator (CWG) Complementary Output Generator (COG)

  • Provides non-overlapping complementary waveform
  • Various input sources inclusive of: Comparators, PWM, CLC, NCO
  • Blanking control for transient filtering (COG only)
  • Phase control for output delay (COG only)
  • Independent rise and fall
  • Dead band control
  • Auto shutdown/restart
  • Polarity control

Numerically Controlled Oscillator (NCO)

  • 20-bit PWM frequency resolution with linear control
  • Independent 16 MHz clock input
  • 16b numeric frequency control
    • – 500 kHz max output
    • – 15 Hz per step
  • 2 output modes
    • Fixed 50% Duty Cycle (FDC)
    • Pulse Frequency Modulation (PFM)

    Configurable Logic Cell (CLC)

    • User configurable real time logic control
      • CLC configuration GUI for quick turn development
    • Combinational Logic Functions
      • AND/OR/XOR/NOT/NAND/NOR/XNOR
    • State Functions/Clock
      • D Flip-Flop, JK Flip-Flop D Latch, SR Latch
    • Input sources
      • Pins
      • Peripherals
    • Output available to:
      • External pins
      • Other peripherals
    • Operation while in Sleep
    • Configurable via custom GUI

Advanced Peripheral Integration - PIC12F752

    • Flash Program Memory with self read/write capability
    • Mid-Range Core, Internal 8MHz oscillator
    • 2 x High Speed Analog Comparators (20nS)
    • 1 x Capture-Compare-PWM (CCP)
    • 4 x 10-bit Analog-to-Digital Converter (ADC) with voltage reference,
    • 1 x Dual Range 5-bit Digital-to-Analog Converter (DAC)
    • Complementary Output Generator (COG): Complementary Waveforms from selectable sources
    • Watchdog Timer (WDT)
    • Power-On/Off-Reset, Brown-Out Reset (BOR)
    • In Circuit Serial Programming (ICSP)
    • High Current Source/Sink: 2 pins with 50 mA I/O, 4 pins with 25 mA I/O
    • Wide Operating Voltage of PIC12F752 variant (2.0V – 5.5V)
    • High Voltage PIC12HV752 variant (2.0V – user defined) with internal shunt regulator

Intelligent Analog Integration - PIC16F1787

  • Enhanced Mid-Range Core with 49 Instruction, 16 Stack Levels
  • Flash Program Memory with self read/write capability
  • 256 Bytes of EEPROM
  • Internal 32MHz oscillator
  • 3 x PSMC (Programmable Switch Mode Controller)- Dedicated 16bit PWM- Digital and/or analog feedback control of PWM frequency- Dead-band control / auto-shutdown & restart
  • 4 x Fast Comparators with selectable Voltage Reference
  • 3 x Operation Amplifiers (rail-to-rail in and out)
  • 14 x 12-bit ADC with Voltage Reference
  • 8-bit DAC
  • MI2C / SPI / EUSART w/auto baud
  • 3 x Compare-Capture-PWM
  • Four 8-bit Timer (TMR0/TMR2/TMR4/TMR6)
  • One 16-bit Timer (TMR1)
  • Extended Watchdog Timer (EWDT)
  • Wide Operating Voltage Range:- ‘F’ Version (2.3V – 5.5V)- Low Power ‘LF’ variant (1.8V – 3.6V)
  • 25mA Source/Sink current I/O
  • Enhanced Power-On/Off-Reset
  • Brown-Out Reset (BOR)
  • In Circuit Serial Programming (ICSP)

Digital LED Development Kit

LED lighting designers are being challenged to meet the rapidly expanding demand for green, smart energy technologies while differentiating their products. Microchip’s Digital LED Lighting Development Kit (DM330014)  enables designers to quickly leverage the capabilities and performance of the dsPIC33 ‘GS’ series of Digital Signal Controllers (DSCs), to develop LED lighting products. The dsPIC33 ‘GS’ DSC and this reference design allow developers to create a 100% digitally controlled ballast function, while including advanced features such as dimming and color hue control. The dsPIC33 ‘GS’ DSCs can support an entire system implementation for LED lighting products, including power-conversion circuits, such as AC-to-DC and DC-to-DC conversion, along with functions such as Power Factor Correction (PFC), which are necessary for a complete product and lower the overall system cost.

Benefits offered by the digital-power techniques in this reference design and the dsPIC33 ‘GS’ series of DSCs include:

  • Reduced System Cost via higher integration
  • Higher Efficiency using digital-control techniques
  • Flexible and reusable designs
  • Advanced features implemented in software

Example Applications:

LED lighting applications supported by Microchip’s LED Lighting development Kit include dimmable LCD backlighting, signage, LED replacement of fluorescent tubes and incandescent bulbs, architectural lighting, and automotive lighting applications. Automotive lighting products include exterior applications, such as headlights, daytime running lights and signal lights.

Key features of Microchip’s Digital LED Lighting Development Kit include:

  • Color control for RGB LEDs
  • Supports DMX512 Standard for brightness control
  • Flexible input voltage support, including both Buck and Boost topologies
  • Fully dimmable
  • Full digital control
  • Fault protection
  • Fully controlled with a single dsPIC33FJ16GS504 DSC.

Más información en Microchip

Controladores PIC en Victronics.

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