Freescale Semiconductor, Inc.

Freescale Semiconductor, Inc.

System Description

System Specification

The A/D converter is also used to sense the dc-bus voltage and the drive temperature. The dc-bus voltage is stepped down to a 3.3-V signal level by a resistor network.

The six IGBTs (copack with built-in fly back diode), or MOSFETs, and gate drivers create a compact power stage. The drivers provide the level shifting that is required to drive the high side switch. The PWM technique is used to control motor phase voltage.

2.3 System Specification

The concept of the application is that of a speed-closed loop drive using back-EMF zero crossing technique for position detection. It serves as an example of a sensorless BLDC motor control system using Motorola’s MC68HC908MR32 MCU. It also illustrates the usage of dedicated motor control on-chip peripherals.

The system for BLDC motor control consists of hardware and software. The application uses universal modular motion control development hardware boards, which are provided by Motorola for customer development support. For a description of these hardware boards refer to Appendix A. References 3.,4.,5.,6.,7., and the World Wide Web at:

http://www.motorola.com

There are three board and motor hardware sets for the application:

1.High-Voltage Hardware Set — For variable line voltage 115–230 Vac and medium power (phase current < 2.93 A)

2.Low-Voltage Evaluation Motor Hardware Set — For automotive voltage (12 V) and very low power (phase current < 4 A)

3.Low-Voltage Hardware Set — For automotive voltage (12 V or possibly 42 V) and medium power (phase current < 50 A)

DRM028 — Rev 0

 

Designer Reference Manual

 

 

 

MOTOROLA

System Description

17

 

For More Information On This Product,

 

 

Go to: www.freescale.com

 

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Motorola M68HC08 manual System Specification