Lighting with Microcontroller

1
Lighting with Microcontroller

• July 2004

Paolo Oteri application eng. MCD
2
Types of lamps and ST components
Microcontroller
3
Why Electronic Ballast ?
Electronic ballasts replace the starting and
inductive elements of the conventional system
Conventional Lamp Ballast
Electronic Ballast Circuit blocks
4
Lamp Ballast
Conventional Lamp Ballast

• Major Advantages
• No particular problems on the design
• of the ballast.
• Very simple configuration and design.
• Very low cost circuit.

• Major Drawbacks
• False starts.
• 50/60 Hz Flicker.
• High power consumption.

Electronic Lamp Ballast

• Major Advantages
• Low power consumption (typically about 70 of
  that with conv. Ball.)
• Longer tube life.
• No flicker.
• Less resistive losses.
• Reduced weight.

• Major Drawbacks
• More complex configuration and design.
• Higher initial cost.

5
Light Dimmer

• Demands for variations in the intensity of
  lighting have resulted in a growing market for
  electronic dimming.
• There are various kinds of dimmers available on
  the market such as potentiometer and touch
  dimmers.

6
Light Dimmer
Touch Dimmer - MCU Approach
A more advanced high end version of the Triac
dimmer can be implemented by using a
microcontroller for control. The lamp driving is
similar to the analog system, but the feature
that can be added to the system are a lot, for
example scene definition, actual lighting
intensity memorization, remote control, etc.
7
Light Dimmer
Touch Dimmer - MCU Approach
Possible solution for FT
8
Electronic Ballast with Microcontroler

• What can a micro control ?
• Half-bridge control through L63XX driver
• Current regulation
• Digital communication protocol

9
Complete solution
ST72F264 ST7FLite2 ST7FLite0 ST7Lite1B ST52F513
STTH106 STTH306
STx3NK60Z STx4NK60Z STx6NK60Z STD5NM60 And 500V
STx3NK60Z STx4NK60Z STx6NK60Z STD5NM60 And 500V
CMOS
HV-Level Shifter IC HV-Startup TPR
3.3V/5V Supply 2 LS Driver
µC Ballast Control
BCDHV
Heat Gate
L63XX
Com-munic. Interface DALI
10
Half-bridge control

• Deadtime generator
• Emergency pin
• PWM Frequency
• 30kHz-80kHz
• 120kHz for dimmable
• Duty cycle 50
• Timer resolution
• 100Hz _at_ 120kHz for dimmable
• 1kHz _at_ 80kHz for non dimmable

11
Current regulation

• ADC conversion time
• 5us for non dimmable
• 3us for dimmable
• ADC resolution
• 10-bit for non dimmable
• 10-bit and 13-bit in 0-430mV range for dimmable

12
What can we provide ?
Microcontrollers
ST5
ST7
Power line modem
Evaluation kit
ST7538
13
ST7LITE2/ST7DALI

• Advantages
• 32Mhz 12-bit timer
• Adjustable deadtime with only one external XOR
  gate
• BREAK pin for emergency
• DALI peripheral for communication
• 10-bit (13-bit in 0-430mV range) / 3us ADC
• Dimmable/DALI ballast in ramping production at
  Philips
• Drawbacks
• No deadtime in timer

14
ST7LITE1B

• Advantages
• Fast comparator
• BREAK pin for emergency
• 10-bit / 3us ADC
• Drawbacks
• Not available today
• 8Mhz 12-bit timer (dimmable)

15
ST52F513

• Advantages
• Advanced one pulse mode timer for constant Ton
  control
• ADC 10bit 10uS of conversion time
• One Timer with external and internal Start/Stop
• 2 x 20 MHz 16-bit Timer
• Drawbacks
• Timer resolution is 720Hz (120KHz working
  frequency)

16
Summary for non dimmable
17
Summary for dimmable
18
ST7Lite Family Key Features

• ST7Lite Key features for system cost saving
• AD Converter 8 10-bit Op Amp to adapt to
  signal sensor
• Internal RC Oscillator with 1 accuracy (Cost
  saving)
• LVD, AVD (Low Voltage Detect), For more Safety
  in your system
• Low power modes including Auto Wake Up
• More flexibility with Flash program memory
• SPI communications

• DEVELOPMENT Tools for Software implementation
  
• Low Cost and Real Time Code Debug
• Flash programming ICC mode (IAP and ICP)
• Free C Compiler from Cosmic and Metrowerks

APPLICATIONS Small Home Appliance, Appliance,
UPS, Lighting,
Automotive, Toys
19
ST7Lite Family
ST7Lite3
ST72F264G2
ST7DALI
8k
ST7Lite2
20 Pin
28/32 Pin
ST72F264G1
ST7Lite1
ST7Lite1
4k
16 Pin
ST7Lite0
1.5k
ST7Superlite
1k
16 pins
20 pins
28/32 pins
LEGEND
Under development
Full Production
Samples available
20
STfive
FLASH EEPROM 2.7 5.5 V
Samples available
F513 Flash Data EE 10-Bit Adc / Sci
F514 Super Storage 10-Bit Adc / Sci
F510 Flash 10-Bit Adc Sci
256b Data EE Lfbga 36
1/4Kb Data EE So 20/28, Dip 20, SDip 32
4/8Kb Flash 256b Ram 2x 16-Bit Timer/Pwm 10-Bit
Adc Sci - Spi - I2C - Isp So 16/20/28, Dip 20,
SDip 32
F503 Flash Data EE
F500 Flash Basic
256b Data EE
4/8Kb Flash 256b Ram 2x 16-Bit Timer/Pwm Int.Oscil
lator Spi - I2C Isp 16/20/28 pin So Dip 20,
SDip 32