Intermediate
30 min

Upgrade your power needs with triple step-down conversion based on TPS65263 and MK22FN512VLH12

Buck it right, save power

3xBuck click with Kinetis Clicker

Published Jul 31, 2023

Click board™

3xBuck click

Dev Board

Kinetis Clicker

Compiler

NECTO Studio

MCU

MK22FN512VLH12

Offering voltage control at your fingertips, this cutting-edge solution empowers your gadgets to perform at their best

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Hardware Overview

How does it work?

3xBuck Click is based on the TPS65263, a triple synchronous step-down converter from Texas Instruments with programmable dynamic voltage scaling. This IC contains three independent switching sections, which operate at a fixed frequency of 600kHz. One buck section uses the switching clock, which is 180˚ out-of-phase, with respect to the other two sections. This ensures low input current ripple, as well as the lowered EMI of the power supply itself. The TPS65263 IC has the I2C bus logic section, which allows the output voltage of each converter to be programmed. The output voltage is initially set with feedback voltage divider resistors on each section. The output voltages of the sections are set to 5V, 3.3V, and 1.8V because these values are the most commonly used in embedded applications. As soon as the command is sent via the I2C interface, the logic section of the TPS65263 IC takes over the control, allowing to program the voltage at each of the three outputs between 0.68V to 1.95V, with 10mV steps. This allows the desired output to be fine-tuned according to the application's specific needs, which is powered by the 3xBuck click. The I2C interface is also used to independently retrieve

the Power Good status, the overcurrent, and the die temperature warning for each buck section. There are three completely independent switching sections in the TPS65263 IC, meaning each has its dedicated Enable pin, Soft-Start pin, and loop compensation pin. The Enable pins for each section are routed to mikroBUS™. EN1, EN2, and EN3 are routed to AN, PWM, and INT pins of the mikroBUS™, respectively. This allows the host MCU to control the operation of the 3xBuck Click. Not all three sections share the same characteristics. The output of the 3xBuck click labeled as 1V8 (VOUT1) can withstand up to 3A of current while supplied with 12V across the input terminal. The other two outputs can deliver up to 2A, keeping the output well regulated, well within the 1% margin. However, it should be noted that this is the combined current rating, so if multiple outputs are used, the summed current consumption should not exceed these values. The input voltage should range between 4.5V and 18V, with a remark that it must be sufficiently higher than the selected output voltage to reach the specified voltage and current ratings. The soft-start feature uses a 10nF capacitor at the

dedicated SS pin. Each channel has its own dedicated SS pin, so three pins are used to set the soft start of each channel. The soft-start function prevents the high inrush current on power up, ramping up the output current during the soft-start period, defined by the capacitor. As mentioned, the device features protection functions that allow reliable operation in events such as short circuit protection, overcurrent, overvoltage, and thermal protection. If the connected load draws too much current, the cycle-by-cycle current limit will be activated on both high- and low-side output MOSFETs. If the high current condition persists after 0.5ms, the device will enter the hiccup mode, shutting down completely, then restarting after 14ms. The whole startup sequence will be repeated; if the fault condition persists on the output, this cycle will be repeated. This prevents damage in the case of significant loads connected at the output. The logic voltage level of the 3xBuck click can be selected by switching the SMD jumper labeled VCC SEL to an appropriate position. This allows interfacing with both 3.3V and 5V MCUs, expanding the interfacing options of this board.

3xBuck click hardware overview image

Features overview

Development board

Kinetis 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 ARM Cortex-M4 microcontroller, the MK22FN512VLH12 from NXP Semiconductor, 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 Kinetis Clicker development kit contains the components necessary for the most efficient operation of the same board. In addition to the possibility of choosing the Kinetis Clicker programming method, using USB HID mikroBootloader, or through an external mikroProg connector for Kinetis programmer, the Clicker board also includes a clean and regulated power supply module for the development kit. The USB-MiniAB connection provides 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. Kinetis 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.

Kinetis Clicker double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

ARM Cortex-M4

MCU Memory (KB)

512

Silicon Vendor

NXP

Pin count

64

RAM (Bytes)

131072

Used MCU Pins

mikroBUS™ mapper

Channel 1 Enable
PTB2
AN
NC
NC
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
Channel 2 Enable
PTC1
PWM
Channel 3 Enable
PTD0
INT
NC
NC
TX
NC
NC
RX
I2C Clock
PTB0
SCL
I2C Data
PTB1
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Schematic

3xBuck click Schematic schematic

Step by step

Project assembly

Kinetis Clicker front image hardware assembly

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

Kinetis Clicker front image hardware assembly
GNSS2 Click front image hardware assembly
Prog-cut hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
Kinetis Mini 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
Kinetis Clicker HA MCU/Select 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 3xBuck Click driver.

Key functions:

  • c3xbuck_enable_buck - This function enables desired Buck on the board

  • c3xbuck_disable_buck - This function disables desired Buck on the board

  • c3xbuck_set_voltage - This function sets voltage on desired Buck on the board

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 3xBuck Click example
 * 
 * # Description
 * This example demonstrates the use of the 3 x Buck Click Board.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes the driver and performs the click default configuration.
 * 
 * ## Application Task  
 * Alternates between predefined and default values for the Bucks output and 
 * logs the current set values on the USB UART.
 * 
 * @note
 * The default output voltage on Buck 1 is 1800mV, Buck 2 is 3300mV, and Buck 3 is 5000mV.
 * Configurable output voltage on all Bucks ranges from 680mV to 1950mV.
 * 
 * \author Petar Suknjaja
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "c3xbuck.h"

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

static c3xbuck_t c3xbuck;
static log_t logger;

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    c3xbuck_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.

    c3xbuck_cfg_setup( &cfg );
    C3XBUCK_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    c3xbuck_init( &c3xbuck, &cfg );
    Delay_ms ( 100 );
    
    c3xbuck_default_cfg ( &c3xbuck );
    log_info( &logger, "---- Application Task ----" );
}

void application_task ( void )
{
    //  Task implementation.
    log_printf( &logger, "Setting predefined values : \r\n" );
    log_printf( &logger, "Buck 1 : 1000 mV\r\n");
    log_printf( &logger, "Buck 2 : 1250 mV\r\n");
    log_printf( &logger, "Buck 3 : 1500 mV\r\n");
    
    c3xbuck_set_voltage( &c3xbuck, C3XBUCK_SELECT_BUCK_1, C3XBUCK_OUTPUT_VOLTAGE_1000mV );
    c3xbuck_set_voltage( &c3xbuck, C3XBUCK_SELECT_BUCK_2, C3XBUCK_OUTPUT_VOLTAGE_1250mV );
    c3xbuck_set_voltage( &c3xbuck, C3XBUCK_SELECT_BUCK_3, C3XBUCK_OUTPUT_VOLTAGE_1500mV );
    
    // 10 seconds delay
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    
    log_printf( &logger, "Setting default values: \r\n");
    log_printf( &logger, "Buck 1 : 1800 mV\r\n");
    log_printf( &logger, "Buck 2 : 3300 mV\r\n");
    log_printf( &logger, "Buck 3 : 5000 mV\r\n");
    
    c3xbuck_set_voltage( &c3xbuck, C3XBUCK_SELECT_BUCK_1, C3XBUCK_BUCK_DEFAULT_OUTPUT_VOLTAGE );
    c3xbuck_set_voltage( &c3xbuck, C3XBUCK_SELECT_BUCK_2, C3XBUCK_BUCK_DEFAULT_OUTPUT_VOLTAGE );
    c3xbuck_set_voltage( &c3xbuck, C3XBUCK_SELECT_BUCK_3, C3XBUCK_BUCK_DEFAULT_OUTPUT_VOLTAGE );
    
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
}

int main ( void ) 
{
    /* Do not remove this line or clock might not be set correctly. */
    #ifdef PREINIT_SUPPORTED
    preinit();
    #endif
    
    application_init( );
    
    for ( ; ; ) 
    {
        application_task( );
    }

    return 0;
}

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

Additional Support

Resources

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