Intermediate
30 min

Ensure optimal power delivery with LT3976 and MK64FN1M0VDC12

Step down, Power up!

BUCK Click with Clicker 2 for Kinetis

Published Jul 30, 2023

Click board™

BUCK Click

Dev Board

Clicker 2 for Kinetis

Compiler

NECTO Studio

MCU

MK64FN1M0VDC12

With its compact design and high efficiency, our step-down buck converter is the go-to solution for portable electronic devices, extending battery life while maintaining performance

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Hardware Overview

How does it work?

BUCK Click is based on the LT3976, a buck switching regulator from Analog Devices that accepts a wide input voltage range of up to 40V and steps it down to 3.3V or 5V. BUCK Click communicates with the target microcontroller over the following pins on the mikroBUS™ line: PWM, INT, RS, CS. The LT3976 is an adjustable frequency monolithic buck-switching regulator that accepts a wide input voltage range of up to 40V. Low quiescent current design consumes only

3.3µA of supply current while regulating with no load. Low ripple Burst Mode operation maintains high efficiency at low output currents while keeping the output ripple below 15mV in a typical application. The LT3976 can supply up to 5A of load current and has current limit foldback to limit power dissipation during short-circuit. A low dropout voltage of 500mV is maintained when the input voltage drops below the programmed output voltage, such as during an automotive cold

crank. There are two onboard screw terminals, one for connecting the external input supply and the other for the output. A multiplexer also chooses the resistor used for setting the switching frequency. The multiplexer is used for selecting one of the four different resistors. Each of these resistors, if selected, sets a different switching frequency from 0.4 to 1.6MHz.

BUCK Click hardware overview image

Features overview

Development board

Clicker 2 for Kinetis 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 ARM Cortex-M4F microcontroller, the MK64FN1M0VDC12 from NXP Semiconductors, two mikroBUS™ sockets for Click board™ connectivity, a USB connector, LED indicators, buttons, a JTAG programmer connector, and two 26-pin headers for interfacing with external electronics. Its compact design with clear and easily recognizable silkscreen markings allows you to build gadgets with unique functionalities and

features quickly. Each part of the Clicker 2 for Kinetis development kit contains the components necessary for the most efficient operation of the same board. In addition to the possibility of choosing the Clicker 2 for Kinetis programming method, using a USB HID mikroBootloader or an external mikroProg connector for Kinetis programmer, the Clicker 2 board also includes a clean and regulated power supply module for the development kit. It provides two ways of board-powering; through the USB Micro-B cable, where onboard voltage regulators provide the appropriate voltage levels to each component on the board, or

using a Li-Polymer battery via an onboard battery connector. All communication methods that mikroBUS™ itself supports are on this board, including the well-established mikroBUS™ socket, reset button, and several user-configurable buttons and LED indicators. Clicker 2 for Kinetis 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.

Clicker 2 for Kinetis dimensions image

Microcontroller Overview

MCU Card / MCU

default

Architecture

ARM Cortex-M4

MCU Memory (KB)

1024

Silicon Vendor

NXP

Pin count

121

RAM (Bytes)

262144

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
MUX Address 0 Pin
PB11
RST
Chip Enable
PC4
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
MUX Address 1 Pin
PA10
PWM
Power Good
PB13
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 Click Schematic schematic

Step by step

Project assembly

Clicker 2 for PIC32MZ front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Clicker 2 for Kinetis as your development board.

Clicker 2 for PIC32MZ 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 2 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 via Debug Mode

1. Once the code example is loaded, pressing the "DEBUG" button initiates the build process, programs it on the created setup, and enters Debug mode.

2. After the programming is completed, a header with buttons for various actions within the IDE becomes visible. Clicking the green "PLAY" button starts reading the results achieved with the Click board™. The achieved results are displayed in the Application Output tab.

DEBUG_Application_Output

Software Support

Library Description

This library contains API for BUCK Click driver.

Key functions:

  • buck_switch_frequency - Setting the switching frequency function

  • buck_set_mode - Select buck mode (Disable / Enable)

  • buck_get_power_good - Get state internal comparator function

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 Click example
 * 
 * # Description
 * The demo application displays frequency change and voltage 
 * regulation using a BUCK click.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Configuring clicks and log objects.
 * Settings the click in the default configuration.
 * 
 * ## Application Task  
 * This is a example which demonstrates the use of Buck Click board.
 * Checks if it has reached the set output voltage and sets 
 * a different frequency to the LT3976 chip every 5 sec.
 * 
 * \author Katarina Perendic
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "buck.h"

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

static buck_t buck;
static log_t logger;

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    buck_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.

    buck_cfg_setup( &cfg );
    BUCK_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    buck_init( &buck, &cfg );
    Delay_ms( 100 );

    buck_device_reset( &buck );
    buck_default_cfg( &buck );
}

void application_task ( void )
{
    //  Task implementation.
    if ( buck_get_power_good( &buck ) == 1 )
    {
        log_info( &logger, "----  Power good output voltage!  ----" );
    }
    Delay_ms( 1000 );

    log_info( &logger, "----  Switching frequency 400kHz!  ----" );
    buck_switch_frequency( &buck, BUCK_FREQ_400KHz );
    Delay_ms( 5000 );

    log_info( &logger, "----  Switching frequency 800kHz!  ----" );
    buck_switch_frequency( &buck, BUCK_FREQ_800KHz );
    Delay_ms( 5000 );
}

void main ( void )
{
    application_init( );

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


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

Additional Support

Resources

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