Intermediate
30 min

Bipolar voltage booster made easy with LT3582 and STM32L073RZ

Dual voltage dynamo

Boost-INV Click with Nucleo-64 with STM32L073RZ MCU

Published Feb 26, 2024

Click board™

Boost-INV Click

Dev Board

Nucleo-64 with STM32L073RZ MCU

Compiler

NECTO Studio

MCU

STM32L073RZ

From positive to negative, we've got your voltage covered!

A

A

Hardware Overview

How does it work?

Boost-INV Click is based on the LT3582, a programmable boost and inverting DC/DC converter with OTP memory from Analog Devices. This IC is a dual circuit, offering a boost DC/DC converter and an inverter in one package. The boost converter can provide up to 12.78V on the output while driving the load with up to 350mA. The inverter can provide -13.95V, offering up to 600mA to the connected load, before the current limiting is activated. The boost converter uses an advanced switching scheme with the source-grounded NMOS as the main switching element, controlling the off-time and the peak current. The programmable voltage divider on the output provides the feedback voltage needed for the regulation. The inverter topology allows a single inductor to be used on the output, simplifying the design. As mentioned, the LT3582 features programmable parameters, which can be accessed via the I2C interface. These parameters include configuring the output voltages, power sequencing, and output voltage ramp rates. An onboard OTP non-volatile memory can be programmed with values that will be used at the startup. The command register (CMDR) is reset to 0x00h upon powering up, which turns off the outputs and sets the device to read parameters

stored in the OTP area. If the OTP memory area is empty, it is necessary to set up working parameters first (output voltage, power-up sequence, charging current for the ramp-up capacitors, and more) before using the device. It is worth mentioning that there are three bits in the CMDR register, referred to as RSEL0, RSEL1, and RSEL2 in the LT3582 datasheet, which redirects the device to use either registers or the OTP memory. When set to 0, the device uses parameters stored in the OTP memory. Note that 0x00h is the default value of the CMDR register, meaning settings stored in the OTP will be used by default after powering on. It is possible to dynamically change the values of the output voltages and other configurable working parameters. However, turning off the device (SWOFF bit of the CMDR register) is highly recommended before modifying working parameters since large output voltage changes can cause large current spikes on the switching circuitry if performed in real time while the switching circuit is running. Programming the OTP requires an external power source, which is fairly filtered (possibly with a filtering capacitor on the output). Voltage drop under 13V might trigger the FAULT bit and render the device unusable.

This voltage ranges from 13V to 15V. The Click board™ has the standard 2.54mm (100mil) header. Once the programming voltage is connected (VPP pad), the WOTP bit of the CMDR register initiates the programming. The complete algorithm with a detailed description of the OTP programming procedure can be found in the LT3582 datasheet. An onboard SMD jumper labeled as VSEL allows selection between the 3.3V and 5V power rail from mikroBUS™, routing it to the voltage input pin of the LT3582 IC. The I2C pull-up resistors are also connected to this voltage, allowing communication with both 3.3V and 5V MCUs. The Click board™ also offers the I2C address selection jumper, labeled as the I2C ADD. This jumper selects between two possible 7-bit addresses: the left position sets the I2C slave address to 0x49h, while the right position sets the address to 0x69h. Note that this is the 7-bit address only - to get the complete I2C address, an R/W bit needs to be added at the end. Input screw terminals allow secure connection for the load and are clearly labeled to avoid confusion: the V- pin offers the negative voltage, while the V+ pin outputs positive voltage. GND pins are connected to the common ground of the Click board™.

Boost-INV Click hardware overview image

Features overview

Development board

Nucleo-64 with STM32L073RZ MCU offers a cost-effective and adaptable platform for developers to explore new ideas and prototype their designs. This board harnesses the versatility of the STM32 microcontroller, enabling users to select the optimal balance of performance and power consumption for their projects. It accommodates the STM32 microcontroller in the LQFP64 package and includes essential components such as a user LED, which doubles as an ARDUINO® signal, alongside user and reset push-buttons, and a 32.768kHz crystal oscillator for precise timing operations. Designed with expansion and flexibility in mind, the Nucleo-64 board features an ARDUINO® Uno V3 expansion connector and ST morpho extension pin

headers, granting complete access to the STM32's I/Os for comprehensive project integration. Power supply options are adaptable, supporting ST-LINK USB VBUS or external power sources, ensuring adaptability in various development environments. The board also has an on-board ST-LINK debugger/programmer with USB re-enumeration capability, simplifying the programming and debugging process. Moreover, the board is designed to simplify advanced development with its external SMPS for efficient Vcore logic supply, support for USB Device full speed or USB SNK/UFP full speed, and built-in cryptographic features, enhancing both the power efficiency and security of projects. Additional connectivity is

provided through dedicated connectors for external SMPS experimentation, a USB connector for the ST-LINK, and a MIPI® debug connector, expanding the possibilities for hardware interfacing and experimentation. Developers will find extensive support through comprehensive free software libraries and examples, courtesy of the STM32Cube MCU Package. This, combined with compatibility with a wide array of Integrated Development Environments (IDEs), including IAR Embedded Workbench®, MDK-ARM, and STM32CubeIDE, ensures a smooth and efficient development experience, allowing users to fully leverage the capabilities of the Nucleo-64 board in their projects.

Nucleo 64 with STM32L073RZ MCU double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

ARM Cortex-M0

MCU Memory (KB)

192

Silicon Vendor

STMicroelectronics

Pin count

64

RAM (Bytes)

20480

You complete me!

Accessories

Click Shield for Nucleo-64 comes equipped with two proprietary mikroBUS™ sockets, allowing all the Click board™ devices to be interfaced with the STM32 Nucleo-64 board with no effort. This way, Mikroe allows its users to add any functionality from our ever-growing range of Click boards™, such as WiFi, GSM, GPS, Bluetooth, ZigBee, environmental sensors, LEDs, speech recognition, motor control, movement sensors, and many more. More than 1537 Click boards™, which can be stacked and integrated, are at your disposal. The STM32 Nucleo-64 boards are based on the microcontrollers in 64-pin packages, a 32-bit MCU with an ARM Cortex M4 processor operating at 84MHz, 512Kb Flash, and 96KB SRAM, divided into two regions where the top section represents the ST-Link/V2 debugger and programmer while the bottom section of the board is an actual development board. These boards are controlled and powered conveniently through a USB connection to program and efficiently debug the Nucleo-64 board out of the box, with an additional USB cable connected to the USB mini port on the board. Most of the STM32 microcontroller pins are brought to the IO pins on the left and right edge of the board, which are then connected to two existing mikroBUS™ sockets. This Click Shield also has several switches that perform functions such as selecting the logic levels of analog signals on mikroBUS™ sockets and selecting logic voltage levels of the mikroBUS™ sockets themselves. Besides, the user is offered the possibility of using any Click board™ with the help of existing bidirectional level-shifting voltage translators, regardless of whether the Click board™ operates at a 3.3V or 5V logic voltage level. Once you connect the STM32 Nucleo-64 board with our Click Shield for Nucleo-64, you can access hundreds of Click boards™, working with 3.3V or 5V logic voltage levels.

Click Shield for Nucleo-64 accessories 1 image

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
Chip Enable
PC12
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
NC
NC
INT
NC
NC
TX
NC
NC
RX
I2C Clock
PB8
SCL
I2C Data
PB9
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Schematic

Boost-INV Click Schematic schematic

Step by step

Project assembly

Click Shield for Nucleo-64 accessories 1 image hardware assembly

Start by selecting your development board and Click board™. Begin with the Nucleo-64 with STM32L073RZ MCU as your development board.

Click Shield for Nucleo-64 accessories 1 image hardware assembly
Nucleo 64 with STM32F401RE MCU front image hardware assembly
LTE IoT 5 Click front image hardware assembly
Prog-cut hardware assembly
LTE IoT 5 Click complete accessories setup image hardware assembly
Nucleo-64 with STM32XXX MCU Access MB 1 Mini B Conn - upright/background hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
Necto image step 5 hardware assembly
Necto image step 6 hardware assembly
Clicker 4 for STM32F4 HA MCU Step hardware assembly
Necto No Display image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Debug Image Necto Step hardware assembly

Track your results in real time

Application Output

After loading the code example, pressing the "DEBUG" button builds and programs it on the selected setup.

Application Output Step 1

After programming is completed, a header with buttons for various actions available in the IDE appears. By clicking the green "PLAY "button, we start reading the results achieved with Click board™.

Application Output Step 3

Upon completion of programming, the Application Output tab is automatically opened, where the achieved result can be read. In case of an inability to perform the Debug function, check if a proper connection between the MCU used by the setup and the CODEGRIP programmer has been established. A detailed explanation of the CODEGRIP-board connection can be found in the CODEGRIP User Manual. Please find it in the RESOURCES section.

Application Output Step 4

Software Support

Library Description

This library contains API for Boost-INV Click driver.

Key functions:

  • boostinv_enable - Functions for enable chip

  • boostinv_set_positive_voltage - Functions for set positive output voltage

  • boostinv_set_negative_voltage - Functions for set negative output voltage

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 
 * \brief BoostInv Click example
 * 
 * # Description
 * Changes the positive and negative output voltage. Input Voltage 3.3V.
 * Positive output voltage goes from 3200mV, 7750mV, 12000mV and 7750mV.
 * Negative output voltage goes from -1450mV, -6700mV, -11050mV and -6700mV.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes I2C module and sets EN ( RST ) pin as output.
 * 
 * ## Application Task  
 * Changes the positive and negative output voltage every 5 sec.
 * 
 * \author Luka FIlipovic
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "boostinv.h"

// ------------------------------------------------------------------ VARIABLES

static boostinv_t boostinv;
static log_t logger;

// ------------------------------------------------------ APPLICATION FUNCTIONS

void application_init ( void )
{
    log_cfg_t log_cfg;
    boostinv_cfg_t cfg;

    /** 
     * 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.

    boostinv_cfg_setup( &cfg );
    BOOSTINV_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    boostinv_init( &boostinv, &cfg );
    
    boostinv_default_cfg ( &boostinv );
    log_printf( &logger, "     Boost INV Click\r\n" );
    log_printf( &logger, "-------------------------\r\n" );
    Delay_ms( 100 );
}

void application_task ( void )
{
    // Sets Positive output voltage
    
    log_printf( &logger, " Positive output voltage \r\n" );
    log_printf( &logger, "- - - - - - - - - - - - -\r\n" );
    log_printf( &logger, "          3200 mV\r\n" );
    log_printf( &logger, "-------------------------\r\n" );
    boostinv_set_positive_voltage( &boostinv, BOOSTINV_VOLTAGE_POSITIVE_3200_mV );
    Delay_ms( 5000 );
    
    log_printf( &logger, "          7750 mV\r\n" );
    log_printf( &logger, "-------------------------\r\n" );
    boostinv_set_positive_voltage( &boostinv, BOOSTINV_VOLTAGE_POSITIVE_7750_mV );
    Delay_ms( 5000 );
    
    log_printf( &logger, "        12000 mV\r\n" );
    log_printf( &logger, "-------------------------\r\n" );
    boostinv_set_positive_voltage( &boostinv, BOOSTINV_VOLTAGE_POSITIVE_12000_mV );
    Delay_ms( 5000 );
    
    log_printf( &logger, "         7750 mV\r\n" );
    log_printf( &logger, "-------------------------\r\n" );
    boostinv_set_positive_voltage( &boostinv, BOOSTINV_VOLTAGE_POSITIVE_7750_mV );
    Delay_ms( 5000 );
    
    // Sets Negative output voltage
    
    log_printf( &logger, " Negative output voltage \r\n" );
    log_printf( &logger, "- - - - - - - - - - - - -\r\n" );
    log_printf( &logger, "        -1450 mV\r\n" );
    log_printf( &logger, "-------------------------\r\n" );
    boostinv_set_negative_voltage( &boostinv, BOOSTINV_VOLTAGE_NEGATIVE_1450_mV );
    Delay_ms( 5000 );
    
    log_printf( &logger, "       - 6700 mV\r\n" );
    log_printf( &logger, "-------------------------\r\n" );
    boostinv_set_negative_voltage( &boostinv, BOOSTINV_VOLTAGE_NEGATIVE_6700_mV );
    Delay_ms( 5000 );
    
    log_printf( &logger, "       - 11050 mV\r\n" );
    log_printf( &logger, "-------------------------\r\n" );
    boostinv_set_negative_voltage( &boostinv, BOOSTINV_VOLTAGE_NEGATIVE_11050_mV );
    Delay_ms( 5000 );
    
    log_printf( &logger, "       - 6700 mV\r\n" );
    log_printf( &logger, "-------------------------\r\n" );
    boostinv_set_negative_voltage( &boostinv, BOOSTINV_VOLTAGE_NEGATIVE_6700_mV );
    Delay_ms( 5000 );
}

void main ( void )
{
    application_init( );

    for ( ; ; )
    {
        application_task( );
    }
}


// ------------------------------------------------------------------------ END

Additional Support

Resources