Charger 5 Click is designed to charge Lithium-Ion and Lithium-Polymer batteries. Besides the overvoltage and undervoltage protection, reverse discharge and overtemperature protection, automatic recharge and end of charge safety timer, the Click also introduces the fast charging feature to the line of Click board™ charger products. Charger 5 Click uses a programmable digital potentiometer for adjusting the fast charging constant current, which can be set from 100 mA to 950 mA, via the SPI interface.

Charger 5 Click carries the MCP73113, a single-cell Li-Po/Li-Ion battery charge IC from Microchip, along with the digital potentiometer chip labeled as MCP4161, from the same company. This Click can be used to easily and securely charge and fast-charge batteries on many different devices that use 3.7V Li-Po/Li-Ion batteries.

Charger 5 Click features two integrated circuits, both made by Microchip. One of them is the MCP73113, a single-cell battery charger equipped with many features, optimized for charging of the Li-Po/Li-Ion batteries. The constant charging current on the MCP73113 device is set by a resistor, connected between the PROG pin and the VCC, but instead using the conventional resistor, Charger 5 Click employs the MCP4161 digital potentiometer IC, which allows setting the constant charging current via the SPI interface. This way, the constant charging current can be set from 100mA to 950mA.

The MCP73113 charger IC features a number of different battery charging protection and optimization schemes so that the charging process remains perfectly safe and efficient. The undervoltage protection shuts the charger circuit down in case the connected input voltage is below the threshold value. The overvoltage protection will also put the device in the shutdown mode if the input voltage is greater than the threshold value. Also, the connected input voltage should be 150mV greater than the battery voltage or else it will remain in power down state. This prevents the battery draining in case there's no input voltage. Therefore, the input voltage range should stay between 5V and 6.5V. The device is resistant to voltage spikes up to 18V on its input connector, but for a proper operation, the input voltage should stay in the recommended voltage range.

The connected battery voltage is constantly monitored. If it drops below the charging threshold and if all the other input voltage charging conditions are met, the charging process will start. When the battery is charged to the factory set threshold, the charging will be stopped to prevent battery overcharging. Charging threshold for the MCP73113 charger IC used on this Click is set to 4.2V.

If a Li-Ion battery is discharged to below 3V, it has to be pre-charged with around 10% of the full charge current. This means that the charging current, in this case, will be 10% of the fast charging current set by the MCP4161 digital potentiometer.

Charger 5 Click detects short circuit on the battery connector. The short circuit is also reported in case of a faulty battery cell. If such event occurs, the charger will enter the shutdown mode. The MCP73113 charger IC features thermal management too, which regulates the charging current, based on the die temperature. If the IC die is heated over 150°C, the device will be shut down.

The onboard SMD jumper selector is used to select voltage for the digital potentiometer IC and SPI logic levels. There are also two onboard connectors. One connector is a screw terminal used to connect the external power supply (5V to 6.5V). The other connector is the Li-Po/Li-Ion battery 2.54mm header connector.

• Interface: SPI
• Compatibility: mikroBUS™
• Dimensions: 42.9 x 25.4mm
• Input Voltage: 3.3V or 5V
• Input Voltage Range: Min. 4V, Typ. 5V, Max. 6.5V
• Current Output: Min. 100mA, Max. 950mA
• Operating Ambient Temperature: Min. -40°C, Max. 85°C

• Schematic
• MCP4161 Datasheet
• MCP73113 Datasheet
• mikroSDK
• GitHub