dsPIC30F Family Reference Manual
DS70062C-page 15-2 © 2004 Microchip Technology Inc.
15.1 Introduction
The motor control PWM (MCPWM) module simplifies the task of generating multiple,
synchronized pulse width modulated outputs. In particular, the following power and motion
control applications are supported:
• Three-Phase AC Induction Motor
• Switched Reluctance (SR) Motor
• Brushless DC (BLDC) Motor
• Uninterruptable Power Supply (UPS)
The PWM module has the following features:
• Dedicated time base supports T
CY/2 PWM edge resolution
• Two output pins for each PWM generator
• Complementary or independent operation for each output pin pair
• Hardware dead time generators for complementary mode
• Output pin polarity programmed by device configuration bits
• Multiple output modes:
- Edge aligned mode
- Center aligned mode
- Center aligned mode with double updates
- Single event mode
• Manual override register for PWM output pins
• Hardware fault input pins with programmable function
• Special Event Trigger for synchronizing A/D conversions
• Each output pin associated with the PWM can be individually enabled
15.1.1 MCPWM Module Variants
There are two versions of the MCPWM module depending on the dsPIC30F device that is
selected. There is an 8-output module that is typically found on devices that have 64 or more
pins. A 6-output MCPWM module is also available and is typically found on smaller devices that
have less than 64 pins. A given dsPIC30F device may have more than one MCPWM module.
Please refer to the specific device data sheet for further details.
Table 15-1: Feature Summary: 6-Output MCPWM vs. 8-Output MCPWM
The 6-output MCPWM module is useful for single or 3-phase power application, while the 8
MCPWM can support 4-phase motor applications. Table 15-1 provides a feature summary for
6- and 8-output MCPWM modules. Both modules can support multiple single phase loads. The
8-output MCPWM also provides increased flexibility in an application because it supports two
fault pins and two programmable dead times. These features are discussed in greater detail in
subsequent sections.
A simplified block diagram of the MCPWM module is shown in Figure 15-1.
Feature 6-Output MCPWM Module 8-Output MCPWM Module
I/O Pins 6 8
PWM Generators 3 4
Fault Input Pins 1 2
Dead Time Generators 1 2
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