Handle demanding power requirements easily with MIC45404 and STM32F031K6
Bucktastic performance!
Published Oct 01, 2024
Click board™
Buck 2 Click
Dev Board
Nucleo 32 with STM32F031K6 MCU
Compiler
NECTO Studio
MCU
STM32F031K6
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Hardware Overview
How does it work?
Buck 2 Click is based on the MIC45404, a 19V 5A ultra-low profile DC-to-DC power module by Microchip. This IC is a valley current mode controlled power module, meaning it has a faster response than the traditional peak current mode control, thus a better response to transients. This IC requires minimal external components, making the whole device robust and easy to work with. Unlike traditional switching regulators, this one does not require external feedback components - it is enough to connect the OUTSNS pin to the output voltage directly. This allows for more accurate control over the voltage regulation. Buck 2 click allows configuring certain working parameters, such as the output voltage, current limit threshold, and PWM switching frequency, by changing the states of the dedicated pins. Those pins are routed to the mikroBUS™ socket or equipped with the SMD jumpers so the end user can set them. These pins can be set to the GND, VCC, or left afloat - high impedance mode (HIGH-Z). They are sampled when the internal voltage is stabilized, and their state is latched - further changes will not affect the selected configuration. The output voltage level is selected by the VOSET0 and VOSET1 pins of the MIC45404 IC, routed to the
mikroBUS™ AN and RST pins, respectively. This gives a total of nine possible voltage level combinations. The FREQ pin can change the PWM switching frequency, routed to the PWM pin of the mikroBUS™ socket. The switching frequency is related to the selected output voltage. For this reason, it is routed to the mikroBUS™ socket so that the voltage output and the corresponding frequency for the selected voltage can be set. There are three possible frequency values: 400kHz, 565kHz, and 790kHz. The onboard SMD jumper selects the current limiting, labeled as ILIM SEL. Limiting the current to 3A, 4A, and 5A is possible. The current limiting is instantaneous, and the MIC45404 IC offers current limit and current sensing on both high-side and low-side internal MOSFET switches. It also features a special Hiccup mode, which reduces power dissipation in prolonged overload or short circuit situations. The internal counter is incremented when a low-end MOSFET current limiting event occurs. A PWM cycle with no low-end MOSFET limiting events will decrease the internal counter. If the internal counter reaches 0Fh, both MOSFETs will be tri-stated, and the power to the output will be cut off. After a predetermined wait time has expired,
the MIC45404 IC will be restarted and attempt a new soft-startup sequence. This mechanism ensures that no false overload events are generated. The EN/DLY pin is used to enable the device. A HIGH logic level on this pin will start up the internal sections of the MIC45404 IC. This pin is routed to the mikroBUS™ CS pin, and since it is in an open drain configuration, it is pulled by the resistor to the GND. The PG pin indicates the power good condition of the output. When the voltage on the output (OUTSNS) drops under 90% of the regulated voltage, this pin is set to a LOW logic level, indicating irregular output voltage. An onboard pull-up resistor pulls This pin to a HIGH logic level since it is configured as the open drain output. It is routed to the mikroBUS™ INT pin. Buck 2 click is equipped with two screw terminals to connect the input voltage source and the output load. The input voltage source is selectable between the +5V rail from the mikroBUS™ and the voltage at the input terminal. It also has an onboard LOGIC SEL SMD jumper, used to set up the logic voltage level so that both 3.3V and 5V capable MCUs can be used.
Features overview
Development board
Nucleo 32 with STM32F031K6 MCU board provides an affordable and flexible platform for experimenting with STM32 microcontrollers in 32-pin packages. Featuring Arduino™ Nano connectivity, it allows easy expansion with specialized shields, while being mbed-enabled for seamless integration with online resources. The
board includes an on-board ST-LINK/V2-1 debugger/programmer, supporting USB reenumeration with three interfaces: Virtual Com port, mass storage, and debug port. It offers a flexible power supply through either USB VBUS or an external source. Additionally, it includes three LEDs (LD1 for USB communication, LD2 for power,
and LD3 as a user LED) and a reset push button. The STM32 Nucleo-32 board is supported by various Integrated Development Environments (IDEs) such as IAR™, Keil®, and GCC-based IDEs like AC6 SW4STM32, making it a versatile tool for developers.
Microcontroller Overview
MCU Card / MCU
Architecture
ARM Cortex-M0
MCU Memory (KB)
32
Silicon Vendor
STMicroelectronics
Pin count
32
RAM (Bytes)
4096
You complete me!
Accessories
Click Shield for Nucleo-32 is the perfect way to expand your development board's functionalities with STM32 Nucleo-32 pinout. The Click Shield for Nucleo-32 provides two mikroBUS™ sockets to add any functionality from our ever-growing range of Click boards™. We are fully stocked with everything, from sensors and WiFi transceivers to motor control and audio amplifiers. The Click Shield for Nucleo-32 is compatible with the STM32 Nucleo-32 board, providing an affordable and flexible way for users to try out new ideas and quickly create prototypes with any STM32 microcontrollers, choosing from the various combinations of performance, power consumption, and features. The STM32 Nucleo-32 boards do not require any separate probe as they integrate the ST-LINK/V2-1 debugger/programmer and come with the STM32 comprehensive software HAL library and various packaged software examples. This development platform provides users with an effortless and common way to combine the STM32 Nucleo-32 footprint compatible board with their favorite Click boards™ in their upcoming projects.
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the Nucleo 32 with STM32F031K6 MCU as your development board.
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.
Software Support
Library Description
This library contains API for Buck 2 Click driver.
Key functions:
buck2_set_output_voltage- Function settings output voltagebuck2_get_power_good- Function reads state PG pinbuck2_set_power_mode- Function settings chip mode
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 2 Click example
*
* # Description
* This application demonstrates the use of Buck 2 Click board.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the driver and configures the click board.
*
* ## Application Task
* Sets a different output voltage every 5 seconds then checks if the voltage on
* the output (OUTSNS) drops under 90% of the regulated voltage
* and displays an appropriate message on USB UART.
*
* \author Katarina Perendic
*
*/
// ------------------------------------------------------------------- INCLUDES
#include "board.h"
#include "log.h"
#include "buck2.h"
// ------------------------------------------------------------------ VARIABLES
static buck2_t buck2;
static log_t logger;
// ------------------------------------------------------ APPLICATION FUNCTIONS
void application_init ( void )
{
log_cfg_t log_cfg;
buck2_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.
buck2_cfg_setup( &cfg );
BUCK2_MAP_MIKROBUS( cfg, MIKROBUS_1 );
buck2_init( &buck2, &cfg );
buck2_default_cfg( &buck2 );
}
void application_task ( void )
{
uint8_t pg_state;
buck2_set_output_voltage( &buck2, BUCK2_SET_VOLTAGE_3300mV );
log_printf( &logger, "---- Output voltage is 3300 mV ----\r\n" );
Delay_ms( 5000 );
pg_state = buck2_get_power_good( &buck2 );
if ( pg_state == 0 )
{
log_info( &logger, "---- Voltage of the output dropped under 90%% of the regulated voltage ----" );
}
buck2_set_output_voltage( &buck2, BUCK2_SET_VOLTAGE_2500mV );
log_printf( &logger, "---- Output voltage is 2500 mV ----\r\n" );
Delay_ms( 5000 );
pg_state = buck2_get_power_good( &buck2 );
if ( pg_state == 0 )
{
log_info( &logger, "---- Voltage of the output dropped under 90%% of the regulated voltage ----" );
}
buck2_set_output_voltage( &buck2, BUCK2_SET_VOLTAGE_1800mV );
log_printf( &logger, "---- Output voltage is 1800 mV ----\r\n" );
Delay_ms( 5000 );
pg_state = buck2_get_power_good( &buck2 );
if ( pg_state == 0 )
{
log_info( &logger, "---- Voltage of the output dropped under 90%% of the regulated voltage ----" );
}
buck2_set_output_voltage( &buck2, BUCK2_SET_VOLTAGE_1500mV );
log_printf( &logger, "---- Output voltage is 1500 mV ----\r\n" );
log_printf( &logger, "-----------------------------------\r\n" );
Delay_ms( 5000 );
pg_state = buck2_get_power_good( &buck2 );
if ( pg_state == 0 )
{
log_info( &logger, "---- Voltage of the output dropped under 90%% of the regulated voltage ----" );
}
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
