Buck 19 Click

Buck 19 Click is a compact add-on board that steps down the voltage from its input (supply) to its output (load). This board features the STPD01, a programmable synchronous buck converter from STMicroelectronics, providing power supply in applications following USB power delivery specifications. The STPD01 provides the desired voltage levels required by USB power delivery systems (USB PD 3.0) via I2C serial interface up to 60W output power, more precisely voltages in the range of 3V to 20V with a step of 20mV minimum, and currents from 0.1A to 3A with a minimum in steps of 50mA. It also offers advanced protection features such as overvoltage, overcurrent, and overtemperature detections.

Click Product page

Click library

• Author : Stefan Filipovic
• Date : Aug 2022.
• Type : I2C type

Software Support

We provide a library for the Buck 19 Click as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.

Package can be downloaded/installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Library Description

This library contains API for Buck 19 Click driver.

Standard key functions :

• buck19_cfg_setup Config Object Initialization function.

  void buck19_cfg_setup ( buck19_cfg_t *cfg );

• buck19_init Initialization function.

  err_t buck19_init ( buck19_t *ctx, buck19_cfg_t *cfg );

• buck19_default_cfg Click Default Configuration function.

  err_t buck19_default_cfg ( buck19_t *ctx );

Example key functions :

• buck19_write_register This function writes a desired data to the selected register by using I2C serial interface.

  err_t buck19_write_register ( buck19_t *ctx, uint8_t reg, uint8_t data_in );

• buck19_set_vout This function sets the voltage output.

  err_t buck19_set_vout ( buck19_t *ctx, float vout );

• buck19_set_ilimit This function sets the current limit.

  err_t buck19_set_ilimit ( buck19_t *ctx, uint16_t ilimit );

Example Description

This example demonstrates the use of Buck 19 Click board by iterating through the entire output voltage range.

The demo application is composed of two sections :

Application Init

Initializes the driver and performs the Click default configuration.

void application_init ( void )
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    buck19_cfg_t buck19_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.
    buck19_cfg_setup( &buck19_cfg );
    BUCK19_MAP_MIKROBUS( buck19_cfg, MIKROBUS_1 );
    if ( I2C_MASTER_ERROR == buck19_init( &buck19, &buck19_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }

    if ( BUCK19_ERROR == buck19_default_cfg ( &buck19 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }

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

Application Task

Changes the output voltage every 3 seconds and displays on the USB UART the currently set voltage output value.

void application_task ( void )
{
    static float vout = BUCK19_VOUT_MIN;
    if ( BUCK19_OK == buck19_set_vout ( &buck19, vout ) )
    {
        log_printf ( &logger, " VOUT: %.2f V\r\n\n", vout );
    }
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    vout += 0.5f;
    if ( vout > ( BUCK19_VOUT_MAX + BUCK19_FLOAT_COMPARE_TOLERANCE ) )
    {
        vout = BUCK19_VOUT_MIN;
    }
}

The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.Buck19

Additional notes and informations

Depending on the development board you are using, you may need USB UART Click, USB UART 2 Click or RS232 Click to connect to your PC, for development systems with no UART to USB interface available on the board. UART terminal is available in all MikroElektronika compilers.