Combine TPS62869 and PIC18F97J60 to accomplish the step-down conversion
It is true. These low values are real!
Published Feb 19, 2023
Click board™
Buck 22 Click
Dev. board
PICPLC16 v7a
Compiler
NECTO Studio
MCU
PIC18F97J60
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
PICPLC16 v7a is the seventh generation of PIC development boards, providing an environment for experimenting with industrial devices. It comes with an onboard 8-bit PIC microcontroller, the PIC18F97J60 from Microchip, and a broad set of unique functions, such as the first-ever embedded debugger/programmer over USB-C. The development board also consists of 16 opto-inputs and 16 relays for currents up to 16A. It is well organized and designed so that the end-user has all the necessary elements, such as switches, buttons, indicators, and connectors, in one place. With eight connectors for each port, PICPLC16 v7a
allows you to develop PIC-based industrial, home, or office automation applications more efficiently than ever. Each part of the PICPLC16 v7a development board contains the components necessary for the most efficient operation of the same board. In addition to the advanced integrated CODEGRIP programmer/debugger module, which offers many valuable programming/debugging options and seamless integration with the Mikroe software environment, the board also includes a clean and regulated power supply block for the development board. It can use a wide range of external power sources, including an external 12V
power supply, 7-23V AC or 9-32V DC via DC connector/screw terminals, and a power source via the USB Type-C (USB-C) connector. Communication options such as LIN and Ethernet are also included, alongside the well-established mikroBUS™ standard. PICPLC16 v7a is an integral part of the Mikroe ecosystem for rapid industrial 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
Architecture
PIC
MCU Memory (KB)
128
Silicon Vendor
Microchip
Pin count
100
RAM (Bytes)
3808
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 PICPLC16 v7a as your development board.
Track your results in real time
Application Output
1. Application Output - In Debug mode, the 'Application Output' window enables real-time data monitoring, offering direct insight into execution results. Ensure proper data display by configuring the environment correctly using the provided tutorial.
2. UART Terminal - Use the UART Terminal to monitor data transmission via a USB to UART converter, allowing direct communication between the Click board™ and your development system. Configure the baud rate and other serial settings according to your project's requirements to ensure proper functionality. For step-by-step setup instructions, refer to the provided tutorial.
3. Plot Output - The Plot feature offers a powerful way to visualize real-time sensor data, enabling trend analysis, debugging, and comparison of multiple data points. To set it up correctly, follow the provided tutorial, which includes a step-by-step example of using the Plot feature to display Click board™ readings. To use the Plot feature in your code, use the function: plot(*insert_graph_name*, variable_name);. This is a general format, and it is up to the user to replace 'insert_graph_name' with the actual graph name and 'variable_name' with the parameter to be displayed.
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
Additional Support
Resources
Category:Buck
