DSPIC33FJ16GS204-I/SP View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

DSPIC33FJ16GS204-I/SP

High-Performance, 16-bit Digital Signal Controllers

Microchip Technology 

dsPIC33FJ06GS101/X02 and dsPIC33FJ16GSX02/X04

15.0 HIGH-SPEED PWM

Note:

This data sheet summarizes the features

of the dsPIC33FJ06GS101/X02 and

dsPIC33FJ16GSX02/X04 families of

devices. It is not intended to be a

comprehensive reference source. To

complement the information in this data

sheet, refer to the “dsPIC33F Family

Reference Manual”, Section 43.

“High- Speed PWM” (DS70323), which is

available on the Microchip web site

(www.microchip.com).

The high-speed PWM module on the

dsPIC33FJ06GS101/X02 and dsPIC33FJ16GSX02/

X04 devices supports a wide variety of PWM modes

and output formats. This PWM module is ideal for

power conversion applications, such as:

• AC/DC Converters

• DC/DC Converters

• Power Factor Correction(PFC)

• Uninterruptible Power Supply (UPS)

• Inverters

• Battery Chargers

• Digital Lighting

15.1 Features Overview

The high-speed PWM module incorporates the

following features:

• 2-4 PWM generators with 4-8 outputs

• Individual time base and duty cycle for each of the

eight PWM outputs

• Dead time for rising and falling edges:

• Duty cycle resolution of 1.04 ns at 40 MIPS

• Dead-time resolution of 1.04 ns at 40 MIPS

• Phase shift resolution of 1.04 ns at 40 MIPS

• Frequency resolution of 1.04 ns at 40 MIPS

• PWM modes supported:

- Standard Edge-Aligned

- True Independent Output

- Complementary

- Center-Aligned

- Push-Pull

- Multiphase

- Variable Phase

- Fixed Off-Time

- Current Reset

- Current-Limit

• Independent Fault/Current-Limit inputs for each of

the eight PWM outputs

• Output override control

• Special Event Trigger

• PWM capture feature

• Prescaler for input clock

• Dual trigger from PWM to ADC

• PWMxH, PWMxL output pin swapping

• PWM4H, PWM4L pins remappable

• On-the-fly PWM frequency, duty cycle and phase

shift changes

• Disabling of Individual PWM generators to reduce

power consumption

• Leading-Edge Blanking (LEB) functionality

Note:

Duty cycle, dead-time, phase shift and

frequency resolution is 8.32 ns in

Center-Aligned PWM mode.

Figure 15-1 conceptualizes the PWM module in a

simplified block diagram. Figure 15-2 illustrates how

the module hardware is partitioned for each PWM

output pair for the Complementary PWM mode. Each

functional unit of the PWM module is discussed in

subsequent sections.

The PWM module contains four PWM generators. The

module has up to eight PWM output pins: PWM1H,

PWM1L, PWM2H, PWM2L, PWM3H, PWM3L,

PWM4H and PWM4L. For complementary outputs,

these eight I/O pins are grouped into H/L pairs.

15.2 Feature Description

The PWM module is designed for applications that

require:

• High-resolution at high PWM frequencies

• The ability to drive Standard, Edge-Aligned,

Center-Aligned Complementary mode, and

Push-Pull mode outputs

• The ability to create multiphase PWM outputs

For Center-Aligned mode, the duty cycle, period phase

and dead-time resolutions will be 8 ns.

Two common, medium power converter topologies are

push-pull and half-bridge. These designs require the

PWM output signal to be switched between alternate

pins, as provided by the Push-Pull PWM mode.

Phase-shifted PWM describes the situation where

each PWM generator provides outputs, but the phase

relationship between the generator outputs is

specifiable and changeable.

Multiphase PWM is often used to improve DC/DC

converter load transient response, and reduce the size

of output filter capacitors and inductors. Multiple DC/DC

converters are often operated in parallel, but

phase-shifted in time. A single PWM output operating at

250 kHz has a period of 4 μs, but an array of four PWM

channels, staggered by 1 μs each, yields an effective

switching frequency of 1 MHz. Multiphase PWM

applications typically use a fixed-phase relationship.

Variable phase PWM is useful in Zero Voltage

Transition (ZVT) power converters. Here, the PWM

duty cycle is always 50%, and the power flow is

controlled by varying the relative phase shift between

the two PWM generators.

© 2009 Microchip Technology Inc.

Preliminary

DS70318D-page 197

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