HOW DOES IT WORK?

Charger 27 Click is based on the MP2639B, a Li-Ion or Li-Polymer switching charger from MPS. The charger works in three modes: charge, discharge, and sleep mode. It operates as a switching charger if the input power supply is available. The charger automatically detects the battery voltage and charges the battery in three phases: pre-charge, constant charge, and constant voltage charge. Other features include charge termination and auto-recharge. When the input is absent, the charger can provide a boost voltage to the VIN terminal, the same which is used for the input voltage power supply.

This Click board™ uses a general-purpose I/O to allow the host MCU to control the MP2639B charger. Besides the push button, you can also select charge mode by pulling the MD pin to a LOW logic state and discharge mode by pulling this pin to a HIGH logic state. The charger uses the CHG pin to indicate the host MCU of the charge status and the AOK pin to indicate the valid input supply.

There are several LEDs on the Charger 27 Click. LEDs labeled 1 – 4 represent a fuel gauge. The charge completion indicator is available over the CHG LED, and the valid input supply indicator is available over the AOK LED. The discharge function is enabled by pressing the onboard button for less than 2.5 seconds. If the discharge is enabled, you can turn off this feature by pressing the button longer than 2.5 seconds. You can also set the charge current between 1A and 2A over the ISET SEL jumper.

This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. Also, this 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