AN1857 Freescale Semiconductor / Motorola, AN1857 Datasheet - Page 4

• Manufacturer Part Number: AN1857
• Description: A 3-Phase ac Induction Motor Control System Based on the MC68HC908MR32
• Manufacturer: Freescale Semiconductor / Motorola

Application Note
MC68HC908MR32 Pulse-Width Modulator
4
The pulse-width modulator module (PWMMC) resident on the MR32 is
specifically designed to provide pulse-width modulated outputs to drive
a power stage connected to a dc servo, brushless dc, or 3-phase ac
motor system. The PWMMC module can be partitioned and configured
in several ways, depending on the specific motor control application.
Figure 2
referenced throughout this explanation of the PWMMC generator.
Features of the MR32 PWM include:
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Freescale Semiconductor, Inc.
For More Information On This Product,
Three complementary PWM pairs or six independent PWM
signals
Complementary mode features include:
– Dead-time insertion
– Separate top/bottom pulse-width correction via current
Edge-aligned PWM or center-aligned PWM signals
PWM signal polarity
20-mA current sink capability on all PWM outputs
Manual PWM output control through software
Programmable fault protection
shows a block diagram of the PWMMC module and is
sensing or programmable software bits
10-CH
10-BIT
ADC
Go to: www.freescale.com
Figure 1. MC68HC908MR32 Block Diagram
CPU08
CGM
SIM
SPI
768 BYTES RAM
32K FLASH
13 I/0 PIN
SCI
POLARITY
SIGNALS
LVI
PWMMC
INPUTS
TIMA
TIMB
FAULT
4-CH
2-CH
PWM1
PWM2
PWM3
PWM4
PWM5
PWM6
MOTOROLA
AN1857