Combine TPS62869 and PIC18F47Q10 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
Curiosity HPC
Compiler
NECTO Studio
MCU
PIC18F47Q10
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
Curiosity HPC, standing for Curiosity High Pin Count (HPC) development board, supports 28- and 40-pin 8-bit PIC MCUs specially designed by Microchip for the needs of rapid development of embedded applications. This board has two unique PDIP sockets, surrounded by dual-row expansion headers, allowing connectivity to all pins on the populated PIC MCUs. It also contains a powerful onboard PICkit™ (PKOB), eliminating the need for an external programming/debugging tool, two mikroBUS™ sockets for Click board™ connectivity, a USB connector, a set of indicator LEDs, push button switches and a variable potentiometer. All
these features allow you to combine the strength of Microchip and Mikroe and create custom electronic solutions more efficiently than ever. Each part of the Curiosity HPC development board contains the components necessary for the most efficient operation of the same board. An integrated onboard PICkit™ (PKOB) allows low-voltage programming and in-circuit debugging for all supported devices. When used with the MPLAB® X Integrated Development Environment (IDE, version 3.0 or higher) or MPLAB® Xpress IDE, in-circuit debugging allows users to run, modify, and troubleshoot their custom software and hardware
quickly without the need for additional debugging tools. Besides, it includes a clean and regulated power supply block for the development board via the USB Micro-B connector, alongside all communication methods that mikroBUS™ itself supports. Curiosity HPC development board allows you to create a new application in just a few steps. Natively supported by Microchip software tools, it covers many aspects of prototyping thanks to many number of different Click boards™ (over a thousand boards), the number of which is growing daily.
Microcontroller Overview
MCU Card / MCU
Architecture
PIC
MCU Memory (KB)
128
Silicon Vendor
Microchip
Pin count
40
RAM (Bytes)
3615
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 Curiosity HPC as your development board.
Track your results in real time
Application Output
This Click board can be interfaced and monitored in two ways:
Application Output- Use the "Application Output" window in Debug mode for real-time data monitoring. Set it up properly by following this tutorial.
UART Terminal- Monitor data via the UART Terminal using a USB to UART converter. For detailed instructions, check out this tutorial.
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
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 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
