Current Limit 5 Click

How does it work?

Current Limit 5 Click as its foundation uses the MIC2099, a current-limiting device with an adjustable overcurrent protection feature from Microchip Technology. The MIC2099 offers flexible protection boundaries for systems against input voltage ranging from 2.5V to 5.5V and limits the output load current to a programmed level (up to 1.05A). Additional safety features include thermal shutdown protection to prevent overheating, under-voltage lock-out, a soft start that prevents large current inrush, as well as automatic-on output after a fault condition.

The current-limit switch is virtually ubiquitous in system control and provides a safe means for regulating the current delivered to a load circuit. It allows the load current to increase to a programmed limit but no higher. Typically, the current limit is a function of the voltage across an external resistor, and this voltage serves as the reference for an internal current-limiting amplifier. By replacing the resistor with a digital potentiometer, you can easily program the current limit as performed on this Click board™. For this purpose, the digital potentiometer MCP4561 from Microchip Technology which communicates with the MCU via 2-Wire I2C serial interface, is used to set the resistance on the MIC2099 LIMIT pin, adjusting the current limit for the switch between 0.1A to 1.05A.

Current Limit 5 Click can be enabled or disabled through the EN pin routed to the CS pin of the mikroBUS™ socket; hence, offering a switch operation to turn ON/OFF power delivery to the connected load. It also provides a fault status indication signal, labeled as FLT and routed to the INT pin of the mikroBUS™ socket, alongside its LED indicator marked as FAULT to indicate different fault conditions such as current limit and thermal shutdown.

This Click board™ can operate with both 3.3V and 5V logic voltage levels selected via the VCC SEL jumper. It allows for both 3.3V and 5V capable MCUs to use the communication lines properly. Additionally, there is a possibility for the MIC2099 power supply selection via jumper labeled as VIN SEL to supply the MIC2099 from an external power supply VEXT terminal in the range from 2.5V to 5.5V or with VCC voltage levels from mikroBUS™ power rails. 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.

Specifications

Pinout diagram

This table shows how the pinout on Current Limit 5 Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
	NC	1	AN	PWM	16	NC
	NC	2	RST	INT	15	FLT	Fault Indication
Enable	EN	3	CS	RX	14	NC
	NC	4	SCK	TX	13	NC
	NC	5	MISO	SCL	12	SCL	I2C Clock
	NC	6	MOSI	SDA	11	SDA	I2C Data
Power Supply	3.3V	7	3.3V	5V	10	5V	Power Supply
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

Current Limit 5 Click electrical specifications

Software Support

We provide a library for the Current Limit 5 Click as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.

Package can be downloaded/installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Library Description

This library contains API for Current Limit 5 Click driver.

Key functions

• currentlimit5_set_ilimit This function sets the current limit value by configuring the onboard digital potentiometer.

• currentlimit5_get_fault_pin This function returns the fault pin logic state.

• currentlimit5_enable_limit This function enables the current limiting switch.

Example Description

This example demonstrates the use of Current Limit 5 Click board™ by limiting the current to a certain value and displaying an appropriate message when the current reaches the limit.

void application_task ( void ) 
 { 
     static uint8_t currentlimit_ind = 2; 
     if ( currentlimit5_get_fault_pin ( &currentlimit5 ) ) 
     { 
         if ( currentlimit_ind != 0 ) 
         { 
             log_printf ( &logger, " The switch is in normal operation rnn" ); 
             currentlimit_ind = 0; 
         } 
     } 
     else 
     { 
         if ( currentlimit_ind != 1 ) 
         { 
             log_printf ( &logger, " The switch is in the current limiting or thermal shutdown operation rnn" ); 
             currentlimit_ind = 1; 
         } 
     } 
 }

The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.CurrentLimit5

Additional notes and informations

Depending on the development board you are using, you may need USB UART click, USB UART 2 Click or RS232 Click to connect to your PC, for development systems with no UART to USB interface available on the board. UART terminal is available in all MikroElektronika compilers.

mikroSDK

This Click board™ is supported with mikroSDK – MikroElektronika Software Development Kit. To ensure proper operation of mikroSDK compliant Click board™ demo applications, mikroSDK should be downloaded from the LibStock and installed for the compiler you are using.

For more information about mikroSDK, visit the official page.