HOW DOES IT WORK?

Charger 23 Click is based on the ISL78693, an integrated charger for single-cell Lithium chemistry batteries from Renesas. The ISL78693 functions as a traditional linear charger. As a linear charger, the ISL78693 charges a battery in the Constant Current (CC) and Constant Voltage (CV) profile. Its constant charge current is selectable via onboard jumper CURR SEL between 250 and 500mA. The charge voltage is also characterized by an accuracy of 1% over the entire recommended operating condition range. The charger automatically recharges the battery when the voltage drops below a recharge threshold of 3.3V typically. When the input supply is not present, the ISL78693 draws less than 1µA current from the battery.

This Click board™ communicates with the host MCU using several pins of the mikroBUS™ socket. The charger can be enabled or disabled using the EN pin of the mikroBUS™ socket, offering a switch operation to turn ON/OFF the charger. In addition, the ISL78693 also has two indication signals to indicate the charge status. The ST pin is a status open-drain that turns to a low logic state at the beginning of a charge cycle until the End-of-charge (EOC) condition is qualified. Once the EOC condition is qualified, the ST pin goes to a HIGH logic state. The fault pin (FLT) turns low when fault conditions occur, such as the external battery temperature fault, a charge time fault, or battery removal. Besides mikroBUS™ pins, there is also their visual representation via red and yellow LEDs marked with STATUS and FAULT.

An NTC function is also available to monitor the battery temperature and ensure a safe charging temperature range. Apart from monitoring, it is also possible to detect the removal of the battery. To use this function, it is necessary to switch the SEN EN jumper to the YES position and to connect an external NTC to the SENSE header pins.

This Click board™ can only be operated from a 5V logic voltage level. Therefore, the board must perform appropriate logic voltage conversion before using MCUs with different logic levels. Additionally, there is a possibility for the ISL78693 power supply selection via jumper labeled as VIN SEL to supply the ISL78693 from an external 5V power supply or with a 5V mikroBUS™ power rail. 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