HOW DOES IT WORK?

LED Driver 13 Click as its foundation uses the A80604-1, a multi-output LED driver for automotive applications designed at a switching frequency of 400kHz from Allegro Microsystems. The A80604-1 implements a current-mode boost/SEPIC converter with gate driver for onboard external N-channel MOSFET. Thus, it provides an output current of 150mA per channel at an output voltage of approximately 26V, limited by the input voltage of the A80604-1, which must be in the range of 6V to 18V for proper operation. It also has integrated protection circuitry to guard against output short, overvoltage, LED short-circuit protections, and overtemperature.

This Click board™ offers two ways to implement the LED dimming: analog dimming via an onboard potentiometer or through an external PWM signal applied on the onboard header labeled as PWM, and PWM dimming using a PWM pin from the mikroBUS™ socket. Using the patented Pre-Emptive Boost control, an LED brightness contrast ratio of 15,000:1 can be achieved using PWM dimming at 200Hz. A higher ratio of 150,000:1 is possible when using a combination of PWM and analog dimming. The analog dimming selection can be made by positioning the SMD jumper labeled as ADIM SEL to an appropriate position marked as POT or PWM.

The switching frequency of the A80604-1 can be externally synchronized to an external clock or generated internally - programmed between 260kHz and 2.3MHz. The spread-spectrum technique (with user-programmable dithering range and modulation frequency) is provided to reduce EMI. A clock-out signal, available on the onboard header labeled CLKO, allows other converters to be synchronized to the switching frequency of A80604-1.

As mentioned in the product description, LED Driver 13 Click communicates with MCU using several GPIO pins. The Enable pin, labeled as EN and routed to the CS pin of the mikroBUS™ socket, optimizes power consumption used for power ON/OFF purposes of the board. In addition, it also uses a fault pin labeled as FLT and routed to the INT pin of the mikroBUS™ socket, which indicates the previously mentioned fault conditions to an external system if any fault occurs during operation. This fault signal is also visually indicated via a red LED labeled FAULT. Once the fault is removed, the soft-start process will continue.

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.