Intermediate
30 min

Solve every voltage challenge with LTC3115-2 and PIC32MZ1024EFH064

Boost or buck, your choice!

Buck-Boost 2 Click with PIC32MZ clicker

Published Aug 03, 2023

Click board™

Buck-Boost 2 Click

Dev.Board

PIC32MZ clicker

Compiler

NECTO Studio

MCU

PIC32MZ1024EFH064

Revolutionize your energy management with our avant-garde Buck-Boost combo at your side

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Hardware Overview

How does it work?

Buck-Boost 2 Click is based on the LTC3115-2, a 40V, 2A synchronous buck-boost DC/DC converter from Analog Devices. This IC relies on the advanced four MOSFET switch topology, so it can sustain the regulation when the input voltage is lower and higher than the output voltage, set by the feedback network to 5V. A proprietary switching algorithm ensures a transparent, continuous transition between operating modes. The LTC3115-2 features both forward and reverse current limiting sections. The maximum current available on the output depends on the mode of operation: If the output voltage is greater than the input voltage, the device works in boost mode, and the maximum current is about 0.6A. If the output voltage exceeds the input voltage, the device works in buck mode, and the maximum current available is about 1.4A. Also, the maximum output current is affected by the switching mode, selectable by the MODE pin, routed to the PWM pin of the mikroBUS™. There are two modes available: fixed frequency PWM mode and burst mode. While working in PWM mode, the LTC3115-2 IC uses a fixed frequency determined by the onboard resistor - in the case of the Buck-Boost 2 click, it is fixed at 750kHz. The PWM mode is used when a heavier load is connected to the output

terminal. This mode is set when the PWM/SYNC pin is pulled to a HIGH logic level. This mode allows the maximum current on the output and results in the lowest amount of switching noise and output voltage ripple. This mode provides power for the connected devices while they work in the active mode. The burst mode is used for maintained efficiency when light output loads are used. When the PWM/SYNC pin is pulled to a LOW logic level, the device will work in burst mode. While in burst mode, the variable frequency switching algorithm is used, resulting in a low quiescent current, which allows lowered power consumption - e.g., when the external voltage input is taken from a battery. The error amplifier is powered down in this mode, and the output current should not be greater than allowed, else the output voltage will lose regulation. This mode is perfectly suited to power up various devices while they work in standby mode. When using the synchronization function of the PWM/SYNC pin, the device works in the fixed frequency PWM mode, but the external clock source of the internal PLL section regulates its frequency. This can be useful when special power supply noise requirements must be met. Since the internal PLL can only increase the internal clock frequency, the

external clock signal should be above the frequency set by the onboard resistor (750kHz), taking the sufficient error margin into account. The RUN pin of the LTC3115-2 IC is routed to the mikroBUS™ RST pin and is used to activate the internal logic and switching circuitry. Setting this pin to a HIGH logic level (above 1.21V) will enable both the logic and the switching sections of the LTC3115-2 IC. It is possible to measure and monitor the output voltage of the Buck-Boost 2 by utilizing the voltage divider, with its middle point routed to the AN pin of the mikroBUS™. By applying the calculation from the formula below, it is possible to determine the exact value of the output voltage. It can monitor the output to take appropriate action when the voltage drops or loses regulation. This board allows operation with both 3.3V and 5V MCUs. There is an onboard SMD jumper labeled as VCC SEL, which is used to set the logic voltage (e.g., for the RUN pin) and the input voltage for the LTC3115-2 IC. Another SMD jumper, labeled VIN SEL, selects the voltage chosen by the VCC SEL and the external source connected to the input terminal. The output load should be connected to the output terminal. Two screw terminals allow easy and secure connection of the input and output lines.

Buck-Boost 2 Click hardware overview image

Features overview

Development board

PIC32MZ Clicker is a compact starter development board that brings the flexibility of add-on Click boards™ to your favorite microcontroller, making it a perfect starter kit for implementing your ideas. It comes with an onboard 32-bit PIC32MZ microcontroller with FPU from Microchip, a USB connector, LED indicators, buttons, a mikroProg connector, and a header for interfacing with external electronics. Thanks to its compact design with clear and easy-recognizable silkscreen markings, it provides a fluid and immersive working experience, allowing access anywhere and under

any circumstances. Each part of the PIC32MZ Clicker development kit contains the components necessary for the most efficient operation of the same board. In addition to the possibility of choosing the PIC32MZ Clicker programming method, using USB HID mikroBootloader, or through an external mikroProg connector for PIC, dsPIC, or PIC32 programmer, the Clicker board also includes a clean and regulated power supply module for the development kit. The USB Micro-B connection can provide up to 500mA of current, which is more than enough to operate all onboard

and additional modules. All communication methods that mikroBUS™ itself supports are on this board, including the well-established mikroBUS™ socket, reset button, and several buttons and LED indicators. PIC32MZ Clicker is an integral part of the Mikroe ecosystem, allowing you to create a new application in minutes. Natively supported by Mikroe software tools, it covers many aspects of prototyping thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.

PIC32MZ clicker double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

PIC32

MCU Memory (KB)

1024

Silicon Vendor

Microchip

Pin count

64

RAM (Bytes)

524288

Used MCU Pins

mikroBUS™ mapper

Analog Output
RE4
AN
Chip Enable
RE5
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
PWM Signal/Burst Mode
RB3
PWM
NC
NC
INT
NC
NC
TX
NC
NC
RX
NC
NC
SCL
NC
NC
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Schematic

Buck-Boost 2 Click Schematic schematic

Step by step

Project assembly

PIC32MZ clicker front image hardware assembly

Start by selecting your development board and Click board™. Begin with the PIC32MZ clicker as your development board.

PIC32MZ clicker front image hardware assembly
GNSS2 Click front image hardware assembly
Prog-cut hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
Micro B Connector Clicker Access - upright/background hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
Necto image step 5 hardware assembly
Necto image step 6 hardware assembly
Flip&Click PIC32MZ MCU step hardware assembly
Necto No Display image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Debug Image Necto Step hardware assembly

Track your results in real time

Application Output

After loading the code example, pressing the "DEBUG" button builds and programs it on the selected setup.

Application Output Step 1

After programming is completed, a header with buttons for various actions available in the IDE appears. By clicking the green "PLAY "button, we start reading the results achieved with Click board™.

Application Output Step 3

Upon completion of programming, the Application Output tab is automatically opened, where the achieved result can be read. In case of an inability to perform the Debug function, check if a proper connection between the MCU used by the setup and the CODEGRIP programmer has been established. A detailed explanation of the CODEGRIP-board connection can be found in the CODEGRIP User Manual. Please find it in the RESOURCES section.

Application Output Step 4

Software Support

Library Description

This library contains API for Buck-Boost 2 Click driver.

Key functions:

  • buckboost2_set_mode - This function sets the working mode

  • buckboost2_power_off - This function powers OFF the chip

  • buckboost2_power_on - This function powers on the chip

Open Source

Code example

This example can be found in NECTO Studio. Feel free to download the code, or you can copy the code below.

/*!
 * \file 
 * \brief Buck Boost 2 Click example
 * 
 * # Description
 * This application enables use of DC-DC step-down/step-up regulator (buck/boost).
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes Driver init and turn ON chip and settings mode with improvement current.
 * 
 * ## Application Task  
 * The click has a constant output voltage of 5V, no additional settings are required.
 * 
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "buckboost2.h"

// ------------------------------------------------------------------ VARIABLES

static buckboost2_t buckboost2;
static log_t logger;

// ------------------------------------------------------ APPLICATION FUNCTIONS

void application_init ( void )
{
    log_cfg_t log_cfg;
    buckboost2_cfg_t cfg;

    /** 
     * Logger initialization.
     * Default baud rate: 115200
     * Default log level: LOG_LEVEL_DEBUG
     * @note If USB_UART_RX and USB_UART_TX 
     * are defined as HAL_PIN_NC, you will 
     * need to define them manually for log to work. 
     * See @b LOG_MAP_USB_UART macro definition for detailed explanation.
     */
    LOG_MAP_USB_UART( log_cfg );
    log_init( &logger, &log_cfg );
    log_info(&logger, "---- Application Init ----");

    //  Click initialization.

    buckboost2_cfg_setup( &cfg );
    BUCKBOOST2_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    buckboost2_init( &buckboost2, &cfg );

    buckboost2_power_on( &buckboost2 );
    buckboost2_set_mode( &buckboost2, BUCKBOOST2_WITH_IMPROVEMENT );
}

void application_task ( void )
{
    //  Task implementation.

}

void main ( void )
{
    application_init( );

    for ( ; ; )
    {
        application_task( );
    }
}


// ------------------------------------------------------------------------ END

Additional Support

Resources