Microchip Technology AC164133 Data Sheet
BUCK/BOOST CONVERTER
PICtail™ PLUS DAUGHTER
BOARD USER’S GUIDE
© 2008 Microchip Technology Inc.
DS70336A-page 7
Chapter 1. Introduction
Modern power supplies are becoming smaller, more efficient, more flexible and less
expensive. These desirable enhancements have come about as digital signal controllers
are incorporated into Switch Mode Power Supply (SMPS) designs. Buck converters are
used when the desired output voltage is smaller than the input voltage. Boost converters
are used when the desired output voltage is higher than the input voltage.
expensive. These desirable enhancements have come about as digital signal controllers
are incorporated into Switch Mode Power Supply (SMPS) designs. Buck converters are
used when the desired output voltage is smaller than the input voltage. Boost converters
are used when the desired output voltage is higher than the input voltage.
This chapter introduces and provides an overview of the Buck/Boost Converter PICtail
Plus Daughter Board. The following topics are included in this chapter:
Plus Daughter Board. The following topics are included in this chapter:
• Overview
• Features
1.1
OVERVIEW
The Buck/Boost Converter PICtail Plus Daughter Board (also referred to as Daughter
Board) is a power supply board. It consists of two independent DC/DC synchronous
buck converters and one independent DC/DC boost converter. Figure 1-1 illustrates a
block diagram of the Daughter Board.
Board) is a power supply board. It consists of two independent DC/DC synchronous
buck converters and one independent DC/DC boost converter. Figure 1-1 illustrates a
block diagram of the Daughter Board.
All of the necessary power, drive and control signals are available in the J1 and J2 con-
nectors. The 16-bit 28-pin Starter Development Board can be used to control one inde-
pendent DC/DC synchronous buck converters. This board can also control two buck
stages, or one buck and one boost stage with hardware modification on the 16-bit
28-pin Starter Development Board. Refer to Section 2.4.2 “16-bit 28-pin Starter
Development Board Controls Buck 1 and Boost Stages” for more details.
nectors. The 16-bit 28-pin Starter Development Board can be used to control one inde-
pendent DC/DC synchronous buck converters. This board can also control two buck
stages, or one buck and one boost stage with hardware modification on the 16-bit
28-pin Starter Development Board. Refer to Section 2.4.2 “16-bit 28-pin Starter
Development Board Controls Buck 1 and Boost Stages” for more details.
The block diagram of the Daughter Board using the 16-bit 28-pin Starter Development
Board is shown in Figure 1-2. All three stages of the Buck/Boost Converter PICtail Plus
Daughter Board are controlled by the Explorer 16 Development Board. Figure 1-3
shows a block diagram of the Daughter Board using the Explorer 16 Development
Board.
Board is shown in Figure 1-2. All three stages of the Buck/Boost Converter PICtail Plus
Daughter Board are controlled by the Explorer 16 Development Board. Figure 1-3
shows a block diagram of the Daughter Board using the Explorer 16 Development
Board.
The control boards provide closed-loop Proportional-Integral-Derivative (PID) control in
the software to maintain the desired output voltage level. The dsPIC
the software to maintain the desired output voltage level. The dsPIC
®
DSC device
provides the necessary memory and peripherals for A/D conversion, PWM generation,
analog comparison and general purpose I/O, excluding the need to perform these func-
tions in external circuitry.
analog comparison and general purpose I/O, excluding the need to perform these func-
tions in external circuitry.
SMPS dsPIC
®
DSC devices are specifically designed to provide low-cost and efficient
control for a wide range of power supply topologies. The specialized peripherals
facilitate closed-loop feedback control of switch mode power supplies, providing
communication for remote monitoring and supervisory control.
facilitate closed-loop feedback control of switch mode power supplies, providing
communication for remote monitoring and supervisory control.
The Daughter Board enables the end user to easily transition from analog-to-digital
implementation of the power application. The Daughter Board also aids in rapid
development of buck converter, boost converter, multi-phase buck converter and two
parallel buck converters.
implementation of the power application. The Daughter Board also aids in rapid
development of buck converter, boost converter, multi-phase buck converter and two
parallel buck converters.