Add flexible high-current step-down power for embedded systems with the TPS6286B08 and STM32G474RE
High-current, adjustable step-down power solution for FPGAs, CPUs, and ASICs
Published Oct 16, 2025
Click board™
Smart Buck 8 Click
Dev. board
Nucleo 64 with STM32G474RE MCU
Compiler
NECTO Studio
MCU
STM32G474RE
Fine-tune the output voltage from 0.4V to 1.675V in precise 5mV steps, giving you ultimate control over your power rail
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Hardware Overview
How does it work?
Smart Buck 8 Click is based on the TPS6286B08, a high-frequency, synchronous step-down converter from Texas Instruments designed to deliver excellent transient response over a broad load current range. Operating in pulse width modulation (PWM) mode at medium to heavy loads and automatically entering power save mode at light loads, this device ensures optimal energy efficiency in every operating condition. Its DCS-Control architecture contributes to outstanding load transient performance and tight output voltage regulation, making it highly suitable for applications demanding stable and precise power delivery like supplying core voltages to FPGAs, CPUs, ASICs, and DSPs, as well as for use in machine vision cameras, IP network cameras, and solid-state drives. Smart Buck 8 Click supports an input voltage range from 2.4V to 5.5V at the VIN terminal, where a green VIN LED indicates the presence of external power, and provides an output voltage adjustable from 0.4V to 1.675V with fine 5mV dynamic voltage scaling (DVS) step size via the I2C interface. With a start-up voltage as low as
0.9V and a maximum output current capability of 8A, it can power high-performance digital loads while maintaining thermal stability and robust fault protection. The integrated HICCUP short-circuit protection and thermal shutdown safeguard the system against overloads and excessive temperatures, ensuring reliable operation in demanding environments. This Click board™ is designed in a unique format supporting the newly introduced MIKROE feature called "Click Snap." Unlike the standardized version of Click boards, this feature allows the main sensor/IC/module area to become movable by breaking the PCB, opening up many new possibilities for implementation. Thanks to the Snap feature, the TPS6286B08 can operate autonomously by accessing its signals directly on the pins marked 1-8. Additionally, the Snap part includes a specified and fixed screw hole position, enabling users to secure the Snap board in their desired location. Communication with the host microcontroller is established over an I2C interface supporting clock speeds up to 3.4MHz, with a fixed address of 0x42 and defined read and
write access frames. To optimize power control and operational management, the board also integrates the MAX40200 from Analog Devices, which enables or disables the TPS6286B08 through the dedicated PON pin. A dedicated EN pin allows for external enable/disable control of the entire power module, supporting power domain management in software-controlled power sequencing scenarios. Additionally, there is also a Power Good (PG pin) output that is also routed to an onboard red LED labeled ERROR, which provides real-time visual indication of any voltage irregularities or faults - indicate valid and stable output voltages. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. Also, this Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used as a reference for further development.
Features overview
Development board
Nucleo-64 with STM32G474R MCU offers a cost-effective and adaptable platform for developers to explore new ideas and prototype their designs. This board harnesses the versatility of the STM32 microcontroller, enabling users to select the optimal balance of performance and power consumption for their projects. It accommodates the STM32 microcontroller in the LQFP64 package and includes essential components such as a user LED, which doubles as an ARDUINO® signal, alongside user and reset push-buttons, and a 32.768kHz crystal oscillator for precise timing operations. Designed with expansion and flexibility in mind, the Nucleo-64 board features an ARDUINO® Uno V3 expansion connector and ST morpho extension pin
headers, granting complete access to the STM32's I/Os for comprehensive project integration. Power supply options are adaptable, supporting ST-LINK USB VBUS or external power sources, ensuring adaptability in various development environments. The board also has an on-board ST-LINK debugger/programmer with USB re-enumeration capability, simplifying the programming and debugging process. Moreover, the board is designed to simplify advanced development with its external SMPS for efficient Vcore logic supply, support for USB Device full speed or USB SNK/UFP full speed, and built-in cryptographic features, enhancing both the power efficiency and security of projects. Additional connectivity is
provided through dedicated connectors for external SMPS experimentation, a USB connector for the ST-LINK, and a MIPI® debug connector, expanding the possibilities for hardware interfacing and experimentation. Developers will find extensive support through comprehensive free software libraries and examples, courtesy of the STM32Cube MCU Package. This, combined with compatibility with a wide array of Integrated Development Environments (IDEs), including IAR Embedded Workbench®, MDK-ARM, and STM32CubeIDE, ensures a smooth and efficient development experience, allowing users to fully leverage the capabilities of the Nucleo-64 board in their projects.
Microcontroller Overview
MCU Card / MCU
Architecture
ARM Cortex-M4
MCU Memory (KB)
512
Silicon Vendor
STMicroelectronics
Pin count
64
RAM (Bytes)
128k
You complete me!
Accessories
Click Shield for Nucleo-64 comes equipped with two proprietary mikroBUS™ sockets, allowing all the Click board™ devices to be interfaced with the STM32 Nucleo-64 board with no effort. This way, Mikroe allows its users to add any functionality from our ever-growing range of Click boards™, such as WiFi, GSM, GPS, Bluetooth, ZigBee, environmental sensors, LEDs, speech recognition, motor control, movement sensors, and many more. More than 1537 Click boards™, which can be stacked and integrated, are at your disposal. The STM32 Nucleo-64 boards are based on the microcontrollers in 64-pin packages, a 32-bit MCU with an ARM Cortex M4 processor operating at 84MHz, 512Kb Flash, and 96KB SRAM, divided into two regions where the top section represents the ST-Link/V2 debugger and programmer while the bottom section of the board is an actual development board. These boards are controlled and powered conveniently through a USB connection to program and efficiently debug the Nucleo-64 board out of the box, with an additional USB cable connected to the USB mini port on the board. Most of the STM32 microcontroller pins are brought to the IO pins on the left and right edge of the board, which are then connected to two existing mikroBUS™ sockets. This Click Shield also has several switches that perform functions such as selecting the logic levels of analog signals on mikroBUS™ sockets and selecting logic voltage levels of the mikroBUS™ sockets themselves. Besides, the user is offered the possibility of using any Click board™ with the help of existing bidirectional level-shifting voltage translators, regardless of whether the Click board™ operates at a 3.3V or 5V logic voltage level. Once you connect the STM32 Nucleo-64 board with our Click Shield for Nucleo-64, you can access hundreds of Click boards™, working with 3.3V or 5V logic voltage levels.
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Click board™ Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the Nucleo 64 with STM32G474RE MCU as your development board.
Software Support
Library Description
Smart Buck 8 Click demo application is developed using the NECTO Studio, ensuring compatibility with mikroSDK's open-source libraries and tools. Designed for plug-and-play implementation and testing, the demo is fully compatible with all development, starter, and mikromedia boards featuring a mikroBUS™ socket.
Example Description
This example demonstrates the use of the Smart Buck 8 Click board. The application cyclically adjusts the output voltage between its minimum and maximum values in steps and monitors the PG (Power Good) pin for any fault conditions. It logs any detected faults including undervoltage lockout, thermal warning, or hiccup event status.
Key functions:
smartbuck8_cfg_setup- This function initializes Click configuration structure to initial values.smartbuck8_init- This function initializes all necessary pins and peripherals used for this Click board.smartbuck8_default_cfg- This function executes a default configuration of Smart Buck 8 Click board.smartbuck8_get_pg_pin- This function reads the logic level of the PG (power-good) pin.smartbuck8_read_status- This function reads the value of the STATUS register and returns it via output pointer.smartbuck8_set_vout- This function sets the output voltage by writing a scaled value to the VOUT register.
Application Init
Initializes the logger and the Smart Buck 8 Click driver, and applies the default configuration.
Application Task
Cycles the output voltage up and down between the minimum and maximum supported values. Checks for fault conditions via the PG pin and logs detailed status flags if any fault is detected.
Open Source
Code example
The complete application code and a ready-to-use project are available through the NECTO Studio Package Manager for direct installation in the NECTO Studio. The application code can also be found on the MIKROE GitHub account.
/*!
* @file main.c
* @brief Smart Buck 8 Click example
*
* # Description
* This example demonstrates the use of the Smart Buck 8 Click board. The application cyclically adjusts
* the output voltage between its minimum and maximum values in steps and monitors the PG (Power Good) pin
* for any fault conditions. It logs any detected faults including undervoltage lockout, thermal warning,
* or hiccup event status.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the logger and the Smart Buck 8 Click driver, and applies the default configuration.
*
* ## Application Task
* Cycles the output voltage up and down between the minimum and maximum supported values.
* Checks for fault conditions via the PG pin and logs detailed status flags if any fault is detected.
*
* @author Stefan Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "smartbuck8.h"
static smartbuck8_t smartbuck8;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
smartbuck8_cfg_t smartbuck8_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.
smartbuck8_cfg_setup( &smartbuck8_cfg );
SMARTBUCK8_MAP_MIKROBUS( smartbuck8_cfg, MIKROBUS_1 );
if ( I2C_MASTER_ERROR == smartbuck8_init( &smartbuck8, &smartbuck8_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
if ( SMARTBUCK8_ERROR == smartbuck8_default_cfg ( &smartbuck8 ) )
{
log_error( &logger, " Default configuration." );
for ( ; ; );
}
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
static uint16_t vout = SMARTBUCK8_VOUT_MV_MIN;
static int16_t vout_step = 50;
static uint8_t status = 0;
if ( !smartbuck8_get_pg_pin ( &smartbuck8 ) )
{
log_printf( &logger, "\r\n Fault indication detected via PG pin!\r\n" );
if ( SMARTBUCK8_OK == smartbuck8_read_status ( &smartbuck8, &status ) )
{
if ( status & SMARTBUCK8_STATUS_THERMAL_WARNING )
{
log_printf ( &logger, " Junction temperature is higher than 130C\r\n" );
}
if ( status & SMARTBUCK8_STATUS_HICCUP )
{
log_printf ( &logger, " Device has HICCUP status once\r\n" );
}
if ( status & SMARTBUCK8_STATUS_UVLO )
{
log_printf ( &logger, " The input voltage is less than UVLO threshold (falling edge)\r\n" );
}
}
}
if ( SMARTBUCK8_OK == smartbuck8_set_vout ( &smartbuck8, vout ) )
{
log_printf ( &logger, "\r\n VOUT: %u mV\r\n", vout );
vout += vout_step;
if ( ( vout > SMARTBUCK8_VOUT_MV_MAX ) || ( vout < SMARTBUCK8_VOUT_MV_MIN ) )
{
vout_step = -vout_step;
vout += vout_step;
vout += vout_step;
}
}
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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