Reference Design

the PFC switch in hysteresis current control mode or output is used for switch off PWM1 in DCM. Than PWM1 signal is used directly for switching the PFC switch transistor.

3.3.3 Protection Features

During the startup phase and run phase, some erroneous states can occur. When the DC-bus voltage does not reach the required value or is out of limits then a fault signal is generated. The DC-bus voltage is also checked against limits in run mode. If any of the previously mentioned faults occurs, all modules are disabled, lamps go out, and the fault diode blinks.

3.4 Software Specification

The software is written in C. The software specifications are listed in Table 3-2. A useful feature of this application is the ability to debug software via the MON08 CYCLONE debug tool connected to JP1 header connector. The Real-Time Debugger from Metrowerks can be used as a debug tool.

Table 3-2. Software Specification

 

Dithering control

 

 

Control Algorithm

Current loop control

 

 

 

Voltage loop control

 

 

Target Processor

MC68HC908LB8

 

 

Language

C with some arithmetical functions in assembler

 

 

Compiler

Metrowerks ANSI-C/C++ Compiler for HC08

 

 

MCU Oscillator Frequency

16 MHz (with default software setting)

 

 

MCU Bus Frequency

4 MHz (with default software setting)

 

 

Targeted Hardware

Dimmable Light Ballast With PFC Demo Board

 

 

A detailed description of how to set Debugger for commutation with MON08 CYCLONE is given in Reference [2]. For safe debugging it is recommended use an opto-isolation board connected between the MON08 CYCLONE and the Light Ballast Demo Board. The Opto-isolation Board user manual can be found in Reference [3].

3.5 Hardware Specification

The other system specifications are determined by the target hardware and lamp characteristics. The board and its connections are shown in Chapter 4 Hardware Design.

This hardware set is designed for fluorescent lamp and mains voltage. The specifications for a high voltage hardware and fluorescent lamp set are listed in Table 3-1. The hardware operates on 230 VAC and 110 VAC mains.

Dimmable Light Ballast with Power Factor Correction, Rev. 1

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Freescale Semiconductor

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Freescale Semiconductor M68HC08 manual Software Specification, Hardware Specification, Protection Features

M68HC08 specifications

Freescale Semiconductor, known for its innovative solutions in the field of embedded systems, developed the M68HC08 microcontroller family, which includes the MC68HC908QT2. This 8-bit microcontroller is engineered to meet the demands of diverse applications, including automotive, industrial, and consumer electronics.

The MC68HC908QT2 is designed around Freescale’s M68HC08 core, which is renowned for its efficient and reliable performance. This microcontroller integrates a powerful instruction set, enabling developers to create high-performance applications with relatively low power consumption. The device operates at a clock frequency of up to 3 MHz, which is adequate for various control tasks.

One of the key features of the MC68HC908QT2 is its memory architecture. It includes a 2 KB Flash memory for program storage, representing a significant advantage for developers requiring non-volatile memory. Additionally, it encompasses 128 bytes of EEPROM memory, allowing for data retention even after power loss. The microcontroller also has 256 bytes of RAM for efficient data manipulation during operation.

In terms of input/output capabilities, the MC68HC908QT2 supports a variety of interfacing options. The microcontroller features up to 20 general-purpose I/O pins for flexibility in connecting with peripheral devices. Additionally, it provides multiple analog-to-digital converters (ADC) and timers that facilitate efficient analog signal processing and precise control through timing functions.

The architecture of the MC68HC908QT2 also incorporates sophisticated on-chip peripherals, enhancing its functionality. These peripherals include PWM (Pulse Width Modulation) outputs, which are essential for applications requiring motor control and other precise duty cycle processes. The integrated watchdog timer ensures reliable operation by resetting the system in the event of an application failure.

Moreover, the MC68HC908QT2 is equipped with an efficient power management system, enabling operation in a low-power mode, ideal for battery-powered applications. This microcontroller is packaged in a compact 28-pin dual in-line package (DIP), making it suitable for space-constrained designs.

In summary, the Freescale Semiconductor MC68HC908QT2 microcontroller is distinguished by its robust performance, extensive memory options, and versatile I/O capabilities. Its advanced features, including built-in timers, ADC, and a power management system, make it an exceptional choice for developers seeking to implement reliable and efficient embedded solutions. With its comprehensive architecture, the MC68HC908QT2 remains a popular choice in the landscape of 8-bit microcontrollers.