LED Driver 11 Click

How does it work?

LED Driver 11 Click as its foundation uses the WLMDU9456001JT (172946001), a LED driver based on a non-synchronous floating buck regulator with integrated MOSFET, integrated diode, and a power inductor able to deliver both constant and pulsed currents from Würth Elektronik. It can provide an output current of up to 450mA at an output voltage from 4.5V to 60V limited by the input voltage of the module, which must be equal to or greater than the desired output voltage for proper operation. The WLMDU9456001JT also has integrated protection circuitry to guard against thermal overstress and electrical damage featuring thermal shutdown, input undervoltage lockout, and LED short-circuit protections.

The control loop is based on a current-mode control scheme with the fixed switching frequency, assuring accurate constant current regulation and good EMI performance. The MCP4726 obtains the LED current regulation, a 12-bit digital-to-analog converter from Microchip, which can adjust the LED current up to 450mA. The MCP4726 also integrates EEPROM for storing DAC register and configuration bit values and communicates with the MCU through the I2C 2-Wire interface supporting Standard (100 kHz), Fast (400 kHz), and High-Speed (3.4 MHz) I2C modes. In addition, the WLMDU9456001JT features an integrated switch current limiting mechanism to prevent the LEDs from being overdriven.

This Click board™ offers two ways to implement the LED dimming: analog dimming and PWM dimming. Both methods control the average current flowing through the LEDs. The analog dimming can be achieved by adjusting the LED current by using an external voltage source on the VIN terminal, while the PWM dimming is implemented by direct control of the dimming control signal routed to the PWM pin on the mikroBUS™ socket. Applying a logic level PWM signal to the WLMDU9456001JT DIM pin, the user can control the brightness of the LED string. The maximum frequency of the PWM dimming signal should not exceed a frequency of 80kHz.

Additionally, the under-voltage lockout voltage divider realized with R7 and R8 is not placed. This option can be used if a particular input voltage should be present before turn on or to ensure safe turn-off of the output voltage in the event of an input voltage dip.

This Click board™ can operate with both 3.3V and 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. 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 LED Driver 11 Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
Analog Signal	AN	1	AN	PWM	16	PWM	PWM Signal
	NC	2	RST	INT	15	NC
	NC	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

LED Driver 11 Click electrical specifications

Software Support

We provide a library for the LED Driver 11 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 LED Driver 11 Click driver.

Key functions:

• leddriver11_cfg_setup – Config Object Initialization function.
• leddriver11_init – Initialization function.
• leddriver11_default_cfg – Click Default Configuration function.

Examples description

This example demonstrates the use of LED Driver 11 click board.

void application_task ( void )
{
    static int16_t duty_cnt = 1;
    static int8_t duty_inc = 1;
    float duty = duty_cnt / 10.0;
    
    leddriver11_set_duty_cycle ( &leddriver11, duty );
    log_printf( &logger, "> Duty: %u%%rn", ( uint16_t )( duty_cnt * 10 ) );
    
    Delay_ms( 500 );
    
    if ( 10 == duty_cnt ) 
    {
        duty_inc = -1;
    }
    else if ( 0 == duty_cnt ) 
    {
        duty_inc = 1;
    }
    duty_cnt += duty_inc;
}

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.LEDDriver11

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. The terminal available in all MikroElektronika compilers, or any other terminal application of your choice, can be used to read the message.

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.