Combine TPS62869 and STM32F303VE to accomplish the step-down conversion
It is true. These low values are real!
Published Feb 26, 2023
Click board™
Buck 22 Click
Dev Board
UNI Clicker
Compiler
NECTO Studio
MCU
STM32F303VE
Step down voltage in the most efficient way
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Hardware Overview
How does it work?
Buck 22 Click is based on the TPS62869, a synchronous step-down converter with an I2C interface from Texas Instruments. The TPS62869 base its work on the DCS-Control™ topology and operates in PWM (pulse width modulation) mode for medium to heavy load conditions and Power Save Mode at light load currents. In PWM mode, the converter operates with its nominal switching frequency of 2.4MHz, having a controlled frequency variation over the input voltage range from the VIN terminal from 2.4 up to 5.5V. The DCS-Control™ topology supports both operation modes (PWM and PFM selectable through a serial interface. The transition from PWM mode to Power Save Mode is seamless and without effects on the
output voltage, providing an efficient, adaptive, and high power-density solution. With its DCS-Control™ architecture, excellent load transient performance and tight output voltage accuracy are achieved alongside adjustable output voltage and current ranges from 0.8V to 3.35V and up to 6A on the VOUT terminal with a 10mV step size. As the load current decreases, the TPS62869 enters Power Save Mode operation, which occurs when the inductor current becomes discontinuous, reaching 0A during a switching cycle. In Power Save Mode, the output voltage rises slightly above the nominal output voltage. This Click board™ communicates with MCU using the standard I2C 2-Wire interface to read data and configure
settings, supporting a Fast Mode operation up to 400kHz. Besides, it also possesses the power-good function, routed to the red LED marked as PWR and INT pin of the mikroBUS™ socket, indicating that the output reached regulation. 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. However, the 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
UNI Clicker is a compact development board designed as a complete solution that brings the flexibility of add-on Click boards™ to your favorite microcontroller, making it a perfect starter kit for implementing your ideas. It supports a wide range of microcontrollers, such as different ARM, PIC32, dsPIC, PIC, and AVR from various vendors like Microchip, ST, NXP, and TI (regardless of their number of pins), four mikroBUS™ sockets for Click board™ connectivity, a USB connector, LED indicators, buttons, a debugger/programmer connector, and two 26-pin headers for interfacing with external electronics. Thanks to innovative manufacturing technology, it allows you to build
gadgets with unique functionalities and features quickly. Each part of the UNI Clicker development kit contains the components necessary for the most efficient operation of the same board. In addition to the possibility of choosing the UNI Clicker programming method, using a third-party programmer or CODEGRIP/mikroProg connected to onboard JTAG/SWD header, the UNI Clicker board also includes a clean and regulated power supply module for the development kit. It provides two ways of board-powering; through the USB Type-C (USB-C) connector, where onboard voltage regulators provide the appropriate voltage levels to each component on the board, or using a Li-Po/Li
Ion battery via an onboard battery connector. All communication methods that mikroBUS™ itself supports are on this board (plus USB HOST/DEVICE), including the well-established mikroBUS™ socket, a standardized socket for the MCU card (SiBRAIN standard), and several user-configurable buttons and LED indicators. UNI 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.
Microcontroller Overview
MCU Card / MCU
Type
8th Generation
Architecture
ARM Cortex-M4
MCU Memory (KB)
512
Silicon Vendor
STMicroelectronics
Pin count
100
RAM (Bytes)
81920
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 UNI Clicker 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 22 Click driver.
Key functions:
buck22_set_vout - This function sets the output voltage by using I2C serial interface.
buck22_read_vout - This function reads the output voltage by using I2C serial interface.
buck22_get_pg_pin - This function returns the power good (PG) pin logic state.
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 Buck 22 Click example
*
* # Description
* This example demonstrates the use of Buck 22 click by changing the output voltage.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the driver and sets the control settings.
*
* ## Application Task
* Changes the output voltage every 3 seconds and displays on the USB UART
* the currently set voltage output value. It also checks the power good pin indicator.
*
* @author Stefan Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "buck22.h"
static buck22_t buck22;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
buck22_cfg_t buck22_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.
buck22_cfg_setup( &buck22_cfg );
BUCK22_MAP_MIKROBUS( buck22_cfg, MIKROBUS_1 );
if ( I2C_MASTER_ERROR == buck22_init( &buck22, &buck22_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
if ( BUCK22_ERROR == buck22_set_control ( &buck22, BUCK22_CONTROL_DEFAULT_SETTING ) )
{
log_error( &logger, " Set control." );
for ( ; ; );
}
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
if ( !buck22_get_pg_pin ( &buck22 ) )
{
log_info ( &logger, " Device is shut down. " );
while ( !buck22_get_pg_pin ( &buck22 ) );
log_info ( &logger, " Device is powered up. " );
}
static uint16_t vout_mv = BUCK22_VOUT_MIN;
if ( BUCK22_OK == buck22_set_vout ( &buck22, vout_mv ) )
{
if ( BUCK22_OK == buck22_read_vout ( &buck22, &vout_mv ) )
{
log_printf ( &logger, " Vout: %u mV\r\n", vout_mv );
}
}
vout_mv += 100;
if ( vout_mv > BUCK22_VOUT_MAX )
{
vout_mv = BUCK22_VOUT_MIN;
}
Delay_ms ( 3000 );
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
