Charger 16 Click

How does it work?

Charger 16 Click as its foundation uses the LT1571, a current-mode PWM step-down (buck) charger from Analog Devices. This battery charger represents a simple, efficient solution to fast-charge rechargeable batteries, including lithium-ion (Li-Ion), nickel-metal-hydride (NiMH), and nickel-cadmium (NiCd) using constant-current and/or constant-voltage control. The internal switch is capable of delivering a 1.5A DC (2A peak current). A saturating switch operates at 500kHz, which provides high efficiency and a small charger size.

Charger 16 Click communicates with MCU using two GPIO pins. The Enable pin, labeled as EN and routed to the CS pin of the mikroBUS™ socket, optimizes power consumption and is used for power ON/OFF purposes (driver operation permission). The onboard current sense resistor (R7) allows simple charge current programming to within 5% accuracy. Charge current can be programmed with the PWM from the mikroBUS™ socket by pulse width modulating current on a PROG pin with a switch Q2 to R7 at a frequency higher than a few kHz. Charge current will be proportional to the duty cycle of Q2 with full-current at 100% duty cycle.

This Click board™ also comes with an indication, red LED labeled as CHARGE, for battery near full-charge state, when the charge current drops to 20% of the programmed value, and selectable constant voltage for 4.1V or 4.2V per cell with 0.6% accuracy. Selection can be performed by onboard SMD jumper labeled as CELL SEL. Besides, the charge termination-flag threshold can be reduced from the default 20% level to as low as 7.5% of the programmed full charge current by positioning an onboard R5 resistor of appropriate value.

The Charger 16 Click supports an external power supply for the LT1571, which can be connected to the input terminal labeled as VIN and should be within the range of 8V to 20V. When the input voltage is removed, its supply voltage pin drops to 0.7V below the battery voltage forcing the charger into a low-battery drain (5mA typical) Sleep mode.

This Click board™ operates only with a 5V logic voltage level. The board must perform appropriate logic voltage level conversion before use with MCUs with different logic levels. However, the Click board™ comes equipped with a library containing functions and an example code that can be used, as a reference, for further development.

Specifications

Pinout diagram

This table shows how the pinout on Charger 16 Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
	NC	1	AN	PWM	16	PWM	PWM Signal
	NC	2	RST	INT	15	NC
Enable	EN	3	CS	RX	14	NC
	NC	4	SCK	TX	13	NC
	NC	5	MISO	SCL	12	NC
	NC	6	MOSI	SDA	11	NC
	NC	7	3.3V	5V	10	5V	Power Supply
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

Charger 16 Click electrical specifications

Software Support

We provide a library for the Charger 16 Click as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.

Package can be downloaded/installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Library Description

This library contains API for Charger 16 Click driver.

Key functions:

• charger16_cfg_setup – Config Object Initialization function.
• charger16_init – Initialization function.
• charger16_default_cfg – Click Default Configuration function.

Examples description

This library contains API for the Charger 16 Click driver. This demo application shows use of a Charger 16 Click board™.

void application_task ( void ) 
{
    log_printf( &logger, "-----------------rn" );
    log_printf( &logger, " Enable charging rn" );
    charger16_enable_charging( &charger16 );
    Delay_ms( 10000 );

    log_printf( &logger, "------------------rn" );
    log_printf( &logger, " Disable charging rn" );
    charger16_disable_charging( &charger16 );
    Delay_ms( 10000 );
}

The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.Charger16

Additional notes and informations

Depending on the development board you are using, you may need USB UART click, USB UART 2 click or RS232 click to connect to your PC, for development systems with no UART to USB interface available on the board. The terminal available in all MikroElektronika compilers, or any other terminal application of your choice, can be used to read the message.

mikroSDK

This Click board™ is supported with mikroSDK – MikroElektronika Software Development Kit. To ensure proper operation of mikroSDK compliant Click board™ demo applications, mikroSDK should be downloaded from the LibStock and installed for the compiler you are using.

For more information about mikroSDK, visit the official page.