30 min

Experience seamless buck-boost power control with MIC7401 and PIC18F86J55

Master the art of voltage regulation

Buck & Boost Click with UNI-DS v8

Published Aug 03, 2023

Click board™

Buck & Boost Click

Development board



NECTO Studio



Achieve exceptional load regulation, ensuring stable output voltage under varying load conditions for precision-driven applications



Hardware Overview

How does it work?

Buck & Boost Click is based on the MIC7401, a powerful highly-integrated configurable power management (PMIC) featuring buck and boost regulators and a high-speed I2C interface with an internal EEPROM memory and micro-power shutdown function from Microchip. This Click board™ has five 3A synchronous buck regulators with high-speed adaptive on-time control and one boost regulator that provides a flash-memory programming supply that delivers up to 200mA of output current. The boost has an output disconnect switch that opens if a short-to-ground fault is detected. The MIC7401 offers two distinct modes of operation, Standby, and Normal mode, intended to provide an energy-optimized solution suitable for portable handheld and infotainment applications. In Normal mode, the programmable switching converters can be configured to support

a variety of Start-up sequencing, timing, soft-start ramp, output voltage levels, current limit levels, and output discharge for each channel. In Standby mode, this PMIC can be configured in a low-power state by turning off the output or changing the output voltage to a lower level. Independent exit from Standby mode can be achieved by I2C communication or the STB pin of the mikroBUS™ socket. Buck & Boost Click communicates with MCU using the standard I2C 2-Wire interface with a frequency of up to 100kHz in the Standard, up to 400 kHz in the Fast, and up to 3.4MHz in the High-Speed mode. This Click board™ also contains additional functionalities routed to the CS, AN, PWM, and INT pins on the mikroBUS™ socket. CS pin labeled EN represents an enable pin that shuts down the device for additional power savings. The PWM pin labeled as STB represents the Standby

Reset function that reduces the total power consumption by either lowering a supply voltage or turning it off. In addition to these functions, this Click board™ has Power-On Reset that goes high after the POR delay time elapses, as well as Global Power-Good output that is pulled high when all the regulator's power-good flags are high. This Click board™ is designed to be operated with 5V logic voltage level from mikroBUS™ or a voltage from an external input terminal in the range from 2.4 to 5.5V that can be selected via the VIN SEL jumper. In this way, using a logic voltage level from a mikroBUS™ socket or an external voltage supply allows both 3.3V and 5V capable MCUs to use the I2C communication lines properly.

Buck & Boost Click hardware overview image

Features overview

Development board

UNI-DS v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports a wide range of microcontrollers, such as different STM32, Kinetis, TIVA, CEC, MSP, PIC, dsPIC, PIC32, and AVR MCUs regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer over WiFi. The development board is well organized and designed so that the end-user has all the necessary elements, such as switches, buttons, indicators, connectors, and others, in one place. Thanks to innovative manufacturing technology, UNI-DS v8 provides a fluid and immersive working experience, allowing access anywhere and under any

circumstances at any time. Each part of the UNI-DS v8 development board contains the components necessary for the most efficient operation of the same board. An advanced integrated CODEGRIP programmer/debugger module offers many valuable programming/debugging options, including support for JTAG, SWD, and SWO Trace (Single Wire Output)), and seamless integration with the Mikroe software environment. Besides, it also includes a clean and regulated power supply module for the development board. It can use a wide range of external power sources, including a battery, an external 12V power supply, and a power source via the USB Type-C (USB-C) connector. Communication options such as USB-UART, USB

HOST/DEVICE, CAN (on the MCU card, if supported), and Ethernet is also included. In addition, it also has the well-established mikroBUS™ standard, a standardized socket for the MCU card (SiBRAIN standard), and two display options for the TFT board line of products and character-based LCD. UNI-DS v8 is an integral part of the Mikroe ecosystem for rapid development. Natively supported by Mikroe software tools, it covers many aspects of prototyping and development thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.

UNI-DS v8 horizontal image

Microcontroller Overview

MCU Card / MCU



8th Generation



MCU Memory (KB)


Silicon Vendor


Pin count


RAM (Bytes)


Used MCU Pins

mikroBUS™ mapper

Power-ON Reset
Standby Mode
Power Good Indicator
I2C Clock
I2C Data
Power Supply

Take a closer look


Buck & Boost Click Schematic schematic

Step by step

Project assembly

Fusion for PIC v8 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the UNI-DS v8 as your development board.

Fusion for PIC v8 front image hardware assembly
GNSS2 Click front image hardware assembly
SiBRAIN for PIC32MZ1024EFK144 front image hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
v8 SiBRAIN Access MB 1 - upright/background hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
NECTO Compiler Selection Step Image hardware assembly
NECTO Output Selection Step Image hardware assembly
Necto image step 6 hardware assembly
Necto image step 7 hardware assembly
Necto image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Necto PreFlash Image hardware assembly

Track your results in real time

Application Output

After pressing the "FLASH" button on the left-side panel, it is necessary to open the UART terminal to display the achieved results. By clicking on the Tools icon in the right-hand panel, multiple different functions are displayed, among which is the UART Terminal. Click on the offered "UART Terminal" icon.

UART Application Output Step 1

Once the UART terminal is opened, the window takes on a new form. At the top of the tab are two buttons, one for adjusting the parameters of the UART terminal and the other for connecting the UART terminal. The tab's lower part is reserved for displaying the achieved results. Before connecting, the terminal has a Disconnected status, indicating that the terminal is not yet active. Before connecting, it is necessary to check the set parameters of the UART terminal. Click on the "OPTIONS" button.

UART Application Output Step 2

In the newly opened UART Terminal Options field, we check if the terminal settings are correct, such as the set port and the Baud rate of UART communication. If the data is not displayed properly, it is possible that the Baud rate value is not set correctly and needs to be adjusted to 115200. If all the parameters are set correctly, click on "CONFIGURE".

UART Application Output Step 3

The next step is to click on the "CONNECT" button, after which the terminal status changes from Disconnected to Connected in green, and the data is displayed in the Received data field.

UART Application Output Step 4

Software Support

Library Description

This library contains API for Buck & Boost Click driver.

Key functions:

  • bucknboost_set_buck_out_voltage - This function sets the output voltage of a desired buck channel

  • bucknboost_set_boost_out_voltage - This function sets the output voltage of the boost channel (CH6)

  • bucknboost_get_status - This function reads Power Good, EEPROM, and Overcurrent status registers

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 main.c
 * @brief BucknBoost Click example
 * # Description
 * This application demonstrates the use of Buck n Boost click board.
 * The demo application is composed of two sections :
 * ## Application Init
 * Initializes the driver and sets the click default configuration.
 * The default config enables the click board and limits the current of all outputs to 1100mA.
 * It also sets the default voltages of all channels which are the following:
 * OUT1 - 1.8V, OUT2 - 1.1V, OUT3 - 1.8V, OUT4 - 1.05V, OUT5 - 1.25V, OUT6 - 12V 
 * ## Application Task
 * Iterates through the entire range of Buck voltages for Buck 1 output starting from the maximal output.
 * It also checks the Power Good and Overcurrent status.
 * All data is being displayed on the USB UART where you can track the program flow.
 * @author Stefan Filipovic

#include "board.h"
#include "log.h"
#include "bucknboost.h"

static bucknboost_t bucknboost;
static log_t logger;

void application_init ( void ) 
    log_cfg_t log_cfg;  /**< Logger config object. */
    bucknboost_cfg_t bucknboost_cfg;  /**< Click config object. */

     * 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.

    bucknboost_cfg_setup( &bucknboost_cfg );
    BUCKNBOOST_MAP_MIKROBUS( bucknboost_cfg, MIKROBUS_1 );
    err_t init_flag = bucknboost_init( &bucknboost, &bucknboost_cfg );
    if ( init_flag == I2C_MASTER_ERROR ) 
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );

    init_flag = bucknboost_default_cfg ( &bucknboost );
    if ( init_flag == BUCKNBOOST_ERROR ) 
        log_error( &logger, " Default Config Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );
    log_info( &logger, " Application Task " );

void application_task ( void ) 
    bucknboost_status_t status_data;
    for ( uint8_t cnt = BUCKNBOOST_BUCK_OUTPUT_VOLTAGE_3300mV; 
          cnt <= BUCKNBOOST_BUCK_OUTPUT_VOLTAGE_800mV; cnt++ )
        err_t error_check = bucknboost_set_buck_out_voltage( &bucknboost, 
                                                             cnt );
        if ( error_check == BUCKNBOOST_ERROR )
            log_error( &logger, " Setting Buck 1 Output Voltage." );
            Delay_ms( 3000 );
            log_printf( &logger, " Buck 1 Output Voltage set to %u mV.\r\n", 3300 - cnt * 50 );
            bucknboost_get_status( &bucknboost, &status_data );
            log_printf( &logger, " Power Good status -" );
            if ( status_data.power_good == BUCKNBOOST_PGOOD_ALL_MASK )
                log_printf( &logger, " Valid!\r\n" );
                log_printf( &logger, " Not Valid! - Mask: 0x%.2X\r\n", ( uint16_t ) status_data.power_good );
            log_printf( &logger, " Overcurrent status -" );
            if ( status_data.power_good == BUCKNBOOST_PGOOD_ALL_MASK )
                log_printf( &logger, " No Fault!\r\n" );
                log_printf( &logger, " Fault! - Mask: 0x%.2X\r\n", ( uint16_t ) status_data.overcurrent_fault );
            log_printf( &logger, "-----------------------------------\r\n" );
        Delay_ms( 2000 );

void main ( void ) 
    application_init( );

    for ( ; ; ) 
        application_task( );

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

Additional Support