Ensure a stable and reliable output voltage with minimal dropout with TPS7A83A and PIC18LF27K40
Unlocking efficiency in voltage control
Published Nov 01, 2023
Click board™
LDO Click
Dev. board
EasyPIC v8
Compiler
NECTO Studio
MCU
PIC18LF27K40
Witness voltage precision and dropout perfection with LDO regulators that set the standard for accurate and efficient voltage control
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Hardware Overview
How does it work?
LDO Click is based on the TPS7A83A, a high-current (2A), low-noise, high-accuracy, and low-dropout linear voltage regulator from Texas Instruments. The TPS7A83A has several features that make it useful in various applications, like high accuracy, high-PSR output, and fast transient response for voltage regulation part, as well as certain internal protections like thermal shutdown and foldback current limit. All these features make this Click board™ a robust solution for many challenging problems in generating a clean, accurate power supply. The TPS7A8300A can be easily enabled using the EN pin of the mikroBUS™ socket, offering a switch operation to turn ON/OFF the TPS7A8300A. It has a pin-programmable output voltage from 0.8V-3.95V with a 50mV resolution, or it can be adjustable from 0.8V-5.2V using an external resistor divider (R9 and R10). The
pin-programmable output voltage is possible thanks to the TCA9534A, an I2C-configurable I/O expander also from Texas Instruments, which, by setting the appropriate voltage setting pins on the TPS7A83A, which are connected to an internal feedback network, programs the regulated output voltage. The TCA9534A expander can also choose the least significant bit (LSB) of its I2C slave address by positioning SMD jumpers labeled ADDR SEL to an appropriate position marked as 0 and 1. The adjustable output voltage is achieved through voltage divider resistors whose corresponding values can be found in the datasheet table. One of the power terminals on the board is the VBIAS terminal, which minimizes the internal charge-pump noise when the internal voltage is clamped, thereby reducing the overall output noise floor. This rail enables the use of
low-input voltage, low-output (LILO) voltage conditions (VEXT=1.2V, VOUT =1V) to reduce the power dissipation of the TPS7A8300A. Using a VBIAS voltage improves DC and AC performance for VEXT≤2.2V. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC SEL jumper. This way, it is allowed for both 3.3V and 5V capable MCUs to use the communication lines properly. Additionally, there is a possibility for the TPS7A83A power supply selection via jumper labeled as VIN SEL to supply the TPS7A83A from an external power supply terminal in the range from 1.1V to 6.5V or with selected mikroBUS™ power rail. 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
EasyPIC v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports many high pin count 8-bit PIC microcontrollers from Microchip, regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer. 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, EasyPIC v8 provides a fluid and immersive working experience, allowing access anywhere and under any
circumstances at any time. Each part of the EasyPIC v8 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 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 DEVICE, and CAN are also included, including the well-established mikroBUS™ standard, two display options (graphical and character-based LCD), and several different DIP sockets. These sockets cover a wide range of 8-bit PIC MCUs, from the smallest PIC MCU devices with only eight up to forty pins. EasyPIC 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
Architecture
PIC
MCU Memory (KB)
128
Silicon Vendor
Microchip
Pin count
28
RAM (Bytes)
3728
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 EasyPIC v8 as your development board.
Software Support
Library Description
This library contains API for LDO Click driver.
Key functions:
ldo_enable_device- This function enables the device by setting the EN pin to HIGH logic stateldo_disable_device- This function disables the device by setting the EN pin to LOW logic stateldo_set_vout- This function sets the voltage output.
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 LDO Click example
*
* # Description
* This example demonstrates the use of LDO Click by changing the output voltage.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the driver and performs the device default configuration.
*
* ## Application Task
* Changes the output voltage every 3 seconds and displays on the USB UART
* the currently set voltage output value.
*
* @note
* In order to have up to 3950mV at VOUT you will need to move the VIN SEL on-board jumper
* to the VEXT position and provide at least 3950mV voltage input at the VEXT terminal.
* Otherwise, the maximum level of VOUT will be limited to 3.3V system voltage.
*
* @author Stefan Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "ldo.h"
static ldo_t ldo;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
ldo_cfg_t ldo_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.
ldo_cfg_setup( &ldo_cfg );
LDO_MAP_MIKROBUS( ldo_cfg, MIKROBUS_1 );
if ( I2C_MASTER_ERROR == ldo_init( &ldo, &ldo_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
if ( LDO_ERROR == ldo_default_cfg ( &ldo ) )
{
log_error( &logger, " Default configuration." );
for ( ; ; );
}
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
static uint16_t vout = LDO_VOUT_MIN;
if ( LDO_OK == ldo_set_vout ( &ldo, vout ) )
{
log_printf ( &logger, " VOUT: %u mV\r\n\n", vout );
}
vout += LDO_VOUT_STEP;
if ( vout > LDO_VOUT_MAX )
{
vout = LDO_VOUT_MIN;
}
Delay_ms ( 1000 );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
}
int main ( void )
{
/* Do not remove this line or clock might not be set correctly. */
#ifdef PREINIT_SUPPORTED
preinit();
#endif
application_init( );
for ( ; ; )
{
application_task( );
}
return 0;
}
// ------------------------------------------------------------------------ END
