LED Driver 11 Click Board™

Product Code: MIKROE-4757

How Does The LED Driver 11 Click Board™ Work? The LED Driver 11 Click Board™ 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 under-voltage 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-analogue 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. The LED Driver 11 Click Board™ offers two ways to implement the LED dimming: analogue dimming and PWM dimming. Both methods control the average current flowing through the LEDs. The analogue 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. The LED Driver 11 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 Type LED Drivers Applications Can be used for colour mixing and backlight application for amusement products, LED status signalization, home automation projects, and many more On-board modules WLMDU9456001JT (172946001) - fully integrated constant current LED driver with the buck switching regulator and inductor in a single package from Würth Elektronik Key Features Adjustable LED current, wide input/output voltage range, PWM/Analog dimming, an integrated shielded inductor, onboard protection circuitry, and more Interface Analog,I2C,PWM Compatibility mikroBUS Click board size L (57.15 x 25.4 mm) Input Voltage 3.3V or 5V, External 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