30 min

Limit currents/voltages to safe levels during fault conditions with TPS259631 and PIC18F85J50

Safeguarding performance, enhancing efficiency

eFuse 2 Click with UNI Clicker

Published Oct 10, 2023

Click board™

eFuse 2 Click

Development board

UNI Clicker


NECTO Studio



Our eFuse device is engineered to revolutionize power management, providing precision control over load voltage and load current to enhance device performance, protect against faults, and ensure reliability



Hardware Overview

How does it work?

eFuse 2 Click is based on the TPS259631, an integrated eFuse device that manages load voltage and load current from Texas Instruments. The TPS259631 provides various factory-programmed settings and user-manageable settings, allowing device configuration to handle different transient and steady-state supply and load fault conditions, thereby protecting the input supply and the downstream circuits connected to the device. The device also uses an in-built thermal shutdown mechanism to shield itself during these fault events. This Click board™ provides a simple solution for current limiting, inrush current control, and supervision of power rails for a wide range of applications operating from 2.7 V to 19 V external power supply and delivering up to 2A. Besides, the eFuse 2 Click board™ monitors the input supply the entire time and comes up with a user-adjustable UVLO and

OVLO mechanism through an I2C compatible digital potentiometer, the AD5241 from Analog Devices to ensure that the load is powered up only when the voltage is at a sufficient level. It is also possible to get an accurate sense of the output load current by measuring the voltage drop across the current limit resistor. By replacing the resistor with a digital rheostat, you can easily program the current limit as performed on this Click board™. For this purpose, the AD5175 single-channel 1024-position digital rheostat from Analog Devices that communicate with the MCU through the I2C serial interface is used to program the current limit. The TPS259631 regulates the current to the set current limit value within the nominal overcurrent response time and exits current limiting when the load current falls below the current limit value. The eFuse 2 Click board™ allows the choice of the least significant bit (LSB) of the I2C addresses for

AD5241 and AD5175. This can be performed by positioning the SMD jumper labeled as ADDR SEL to its appropriate position. Additional functionality, such as hardware reset for AD5175 and fault indication interrupt, is provided and routed at RST and INT pins of the mikroBUS™ socket labeled as RST and FLT. This open-drain fault output is associated with a red LED indicator, marked as the FLT, that will be pulled low when a fault is detected. 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. Also, this 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.

eFuse 2 Click hardware overview image

Features overview

Development board

UNI Clicker is a compact development board designed as a complete solution that brings the flexibility of add-on Click boards™ to your favorite microcontroller, making it a perfect starter kit for implementing your ideas. It supports a wide range of microcontrollers, such as different ARM, PIC32, dsPIC, PIC, and AVR from various vendors like Microchip, ST, NXP, and TI (regardless of their number of pins), four mikroBUS™ sockets for Click board™ connectivity, a USB connector, LED indicators, buttons, a debugger/programmer connector, and two 26-pin headers for interfacing with external electronics. Thanks to innovative manufacturing technology, it allows you to build

gadgets with unique functionalities and features quickly. Each part of the UNI Clicker development kit contains the components necessary for the most efficient operation of the same board. In addition to the possibility of choosing the UNI Clicker programming method, using a third-party programmer or CODEGRIP/mikroProg connected to onboard JTAG/SWD header, the UNI Clicker board also includes a clean and regulated power supply module for the development kit. It provides two ways of board-powering; through the USB Type-C (USB-C) connector, where onboard voltage regulators provide the appropriate voltage levels to each component on the board, or using a Li-Po/Li

Ion battery via an onboard battery connector. All communication methods that mikroBUS™ itself supports are on this board (plus USB HOST/DEVICE), including the well-established mikroBUS™ socket, a standardized socket for the MCU card (SiBRAIN standard), and several user-configurable buttons and LED indicators. UNI Clicker is an integral part of the Mikroe ecosystem, allowing you to create a new application in minutes. Natively supported by Mikroe software tools, it covers many aspects of prototyping thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.

UNI clicker double image

Microcontroller Overview

MCU Card / MCU



8th Generation



MCU Memory (KB)


Silicon Vendor


Pin count


RAM (Bytes)


Used MCU Pins

mikroBUS™ mapper

Power Supply
Fault Interrupt
I2C Clock
I2C Data
Power Supply

Take a closer look


eFuse 2 Click Schematic schematic

Step by step

Project assembly

UNI Clicker front image hardware assembly

Start by selecting your development board and Click board™. Begin with the UNI Clicker as your development board.

UNI Clicker front image hardware assembly
GNSS2 Click front image hardware assembly
SiBRAIN for STM32F745VG front image hardware assembly
Prog-cut hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
UNI Clicker Access MB 1 - 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
Necto image step 7 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 eFuse 2 Click driver.

Key functions:

  • efuse2_set_operating_voltage - Set operating voltage function

  • efuse2_set_current_limit - Set operating current function

  • efuse2_get_fault - Get fault function

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 main.c
 * @brief eFuse2 Click example
 * # Description
 * This is an example that demonstrate the use of the eFuse 2 click board.
 * The demo application is composed of two sections :
 * ## Application Init
 * Initialization driver enables - I2C,
 * AD5175: enable write, set the normal operating mode and operating
 * current to the 1,2 A;
 * AD5241: set operating voltage to the 12,0 V;
 * display diagnostic states.
 * ## Application Task
 * eFuse 2 click board uses USB UART log to display
 * operating voltage, OVLO, UVLO and current limit condition.
 * This firmware provides the functions to set the operating voltage and
 * current limiting conditions in order to provide the threshold
 * of the fault conditions. When one of the fault conditions is met,
 * the microcontroller is notified via INT pin which is checked
 * by the app to initiate a shutdown mode.
 * All data logs write on USB UART changes every 2000 milliseconds.
 * @author Stefan Ilic

#include "board.h"
#include "log.h"
#include "efuse2.h"

static efuse2_t efuse2;
static log_t logger;

float op_current;
float op_voltage;
float min_voltage;
float max_voltage;

void application_init ( void ) {
    log_cfg_t log_cfg;  /**< Logger config object. */
    efuse2_cfg_t efuse2_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.
    efuse2_cfg_setup( &efuse2_cfg );
    EFUSE2_MAP_MIKROBUS( efuse2_cfg, MIKROBUS_1 );
    err_t init_flag = efuse2_init( &efuse2, &efuse2_cfg );
    if ( I2C_MASTER_ERROR == init_flag ) {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );

    efuse2_default_cfg ( &efuse2 );
    Delay_ms( 100 );
    op_current = 1.2;
    op_voltage = 12.0;

    log_printf( &logger, "-----------------------------\r\n" );
    log_printf( &logger, "    Set operating  value:    \r\n" );
    log_printf( &logger, "       Voltage: 12.0 V       \r\n" );
    efuse2_set_operating_voltage( &efuse2, op_voltage, &min_voltage, &max_voltage );
    Delay_ms( 1000 );

    log_printf( &logger, "       Current:  1.2 A       \r\n" );
    log_printf( &logger, "-----------------------------\r\n" );
    efuse2_set_current_limit( &efuse2, op_current );
    Delay_ms( 1000 );

    log_printf( &logger, "    Turn ON Power Supply     \r\n" );
    log_printf( &logger, "-----------------------------\r\n" );
    log_info( &logger, " Application Task " );

void application_task ( void ) {
    if ( EFUSE2_FAULT == efuse2_get_fault( &efuse2 ) ) {
        efuse2_operating_mode( &efuse2, EFUSE2_AD5175_SHUTDOWN_MODE );
        Delay_ms( 1000 );

        log_printf( &logger, "        Shutdown Mode        \r\n" );
        log_printf( &logger, "-----------------------------\r\n" );
        for ( ; ; );

    log_printf( &logger, " Oper. Voltage : %.3f V \r\n", op_voltage );
    log_printf( &logger, " Undervoltage  : %.3f V \r\n", min_voltage );
    log_printf( &logger, " Overvoltage   : %.3f V \r\n", max_voltage );
    log_printf( &logger, " Current Limit : %.3f A \r\n", op_current );
    log_printf( &logger, "-----------------------------\r\n" );
    Delay_ms( 2000 );

void main ( void ) {
    application_init( );

    for ( ; ; ) {
        application_task( );

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

Additional Support