Produce an output voltage less than its input thanks to the MPM3632C and STM32F469II
Voltage on demand
Published Jul 31, 2023
Click board™
Buck 10 Click
Dev Board
Fusion for ARM v8
Compiler
NECTO Studio
MCU
STM32F469II
Discover the transformative magic of our buck converter solution – small in size but with a colossal impact on your power needs!
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Hardware Overview
How does it work?
Buck 10 Click is based on the MPM3632C, an 18V 3A ultra-low profile DC-to-DC power module by Monolithic Power Systems (MPS). This IC is a valley current mode-controlled power module responding faster than the traditional peak current mode control. Therefore it has a better response to transients. This IC requires minimal external components, making the whole device robust and easy to work with. The feedback voltage on the FB pin determines the output voltage. Buck 10 click is equipped with a voltage divider and an SMD jumper labeled OUT SEL. This jumper can connect one of two available voltage divider resistors, setting the output to either 3.3V or 5V. These two voltages are the most commonly used in embedded development. The over-current protection is based on cycle-by-cycle limiting
of the inductor current. If the output voltage starts to drop during the current limiting interval, causing the FB voltage to drop under 84% of the internal reference, the device enters the hiccup mode, shutting down the output. After a fixed period, the device will try to re-enable the output. If the short-circuit condition still exists, it will shut down the output again, repeating the whole process until the short-circuit condition disappears. The hiccup mode greatly reduces the short-circuit current, protecting the device when the output is shorted to ground. Thanks to its ability to work with the high-duty cycle of the internal switching PWM signal, the MPM3632C requires the input voltage to be only about 0.7V above the output voltage to maintain the regulation. However, if the input voltage drops
under 3.1V, the device cannot operate properly. Therefore, the under-voltage protection shuts down the device as a protection measure. The under-voltage protection is disabled once the input voltage exceeds 3.6V. This small hysteresis of 0.5V prevents erratic behavior in border cases. The MPM3632C operates at a very high switching frequency of 3 MHz, which allows a good compromise between the efficiency and the device's size, with no external coil needed and a minimal number of other external components. As mentioned before, the voltage of the power supply at the input terminal should stay within the range between 4V and 18V. However, if the output voltage is set to 5V, the voltage at the input should be approximately 5.7V to 6V at least to provide good regulation at the output.
Features overview
Development board
Fusion for ARM 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 ARM® Cortex®-M based 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, Fusion for ARM v8 provides a fluid and immersive working experience, allowing access anywhere and under any
circumstances at any time. Each part of the Fusion for ARM 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. Fusion for ARM 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.
Microcontroller Overview
MCU Card / MCU
Type
8th Generation
Architecture
ARM Cortex-M4
MCU Memory (KB)
2048
Silicon Vendor
STMicroelectronics
Pin count
176
RAM (Bytes)
393216
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 Fusion for ARM v8 as your development board.
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.
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.
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".
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.
Software Support
Library Description
This library contains API for Buck 10 Click driver.
Key functions:
buck10_set_device_mode- This function enables and disables output of this 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 main.c
* @brief Buck 10 Click Example.
*
* # Description
* Demo application shows basic usage of Buck 10 click.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Configuring clicks and log objects.
* Settings the click in the default configuration.
*
* ## Application Task
* Enable and Disable device every 5 seconds.
*
* @note
* Input voltage recommended range - from 4V to 18V
* Low-side valley current limit - from 3A to 3.9A
* Low-side negative current limit - (-2.5A)
* Output voltage - 3.3V or 5V
*
* @author Stefan Ilic
*
*/
#include "board.h"
#include "log.h"
#include "buck10.h"
static buck10_t buck10; /**< Buck 10 Click driver object. */
static log_t logger; /**< Logger object. */
void application_init ( void ) {
log_cfg_t log_cfg; /**< Logger config object. */
buck10_cfg_t buck10_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.
buck10_cfg_setup( &buck10_cfg );
BUCK10_MAP_MIKROBUS( buck10_cfg, MIKROBUS_1 );
if ( buck10_init( &buck10, &buck10_cfg ) == DIGITAL_OUT_UNSUPPORTED_PIN ) {
log_error( &logger, " Application Init Error. " );
log_info( &logger, " Please, run program again... " );
for ( ; ; );
}
log_info( &logger, " Application Task " );
}
void application_task ( void ) {
buck10_set_device_mode ( &buck10, BUCK10_DEVICE_ENABLE );
log_printf(&logger, "Output:\t ENABLED\r\n");
Delay_ms( 5000 );
buck10_set_device_mode ( &buck10, BUCK10_DEVICE_DISABLE );
log_printf(&logger, "Output:\t DISABLED\r\n");
Delay_ms( 5000 );
}
void main ( void ) {
application_init( );
for ( ; ; ) {
application_task( );
}
}
// ------------------------------------------------------------------------ END
