Buck 20 Click

How does it work?

Buck 20 Click is based on the MP2316, a fully-integrated, synchronous, rectified, step-down switch converter from Monolithic Power Systems (MPS). The MP2316 uses constant-on-time (COT) control to provide a fast transient response and easy loop compensation. It achieves 3A continuous output current over a wide input supply range and has excellent load and line regulation. In addition, it is characterized by high efficiency over a wide range of load output voltage, which can be easily adjusted using a digital potentiometer, the AD5235 from Analog Devices. This Click board™ is suitable for battery-operated applications offering advanced protection features such as undervoltage, overcurrent, short-circuit detection, and thermal shutdown.

Thanks to the AD5235 digital potentiometer, this Click board™ provides the possibility of selecting a decreased output voltage in the range from 1.3V to 5V, with the appropriate command sent via the SPI serial interface. Also, the AD5235 uses a ready RDY pin, routed to the INT pin of the mikroBUS™ socket, for its instruction completion indication. In addition to the SPI interface, the Buck 20 Click also has a device-enable feature, routed to the RST pin of the mikroBUS™ socket, for power ON/OFF purposes optimizing power consumption (converter operation permission).

This Click board™ can operate with both 3.3V and 5V logic voltage levels selected via the VCC SEL jumper. This way, both 3.3V and 5V MCUs can use the communication lines correctly. Additionally, there is a possibility for the MP2316 power supply selection via jumper labeled as VIN SEL to supply the MP2316 from an external power supply terminal in the range from 4V to 19V or with mikroBUS™ power rails. 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

Pinout diagram

This table shows how the pinout on Buck 20 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	NC
MP2316 Enable	RST	2	RST	INT	15	RDY	DIGIPOT Ready
SPI Chip Select	CS	3	CS	RX	14	NC
SPI Clock	SCK	4	SCK	TX	13	NC
SPI Data OUT	SDO	5	MISO	SCL	12	NC
SPI Data IN	SDI	6	MOSI	SDA	11	NC
Power Supply	3.3V	7	3.3V	5V	10	5V	Power Supply
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

Buck 20 Click electrical specifications

Software Support

We provide a library for the Buck 20 Click as well as a demo application (example), developed using Mikroe compilers. The demo can run on all the main Mikroe development boards.

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

Library Description

This library contains API for Buck 20 Click driver.

Key functions

• buck20_set_wiper_1 This function sets wiper 1 to desired value.

• buck20_enable_device This function enables the buck device by setting the RST pin to high logic state.

• buck20_disable_device This function disables the buck device by setting the RST pin to low logic state.

Example Description

This example demonstrates the use of Buck 20 Click board™ by changing the output voltage.

void application_task ( void ) 
 { 
     static uint16_t digipot_wiper = BUCK20_WIPER_ZERO_SCALE; 
     float buck_r1_kohm, buck_vout; 
     if ( BUCK20_OK == buck20_set_wiper_1 ( &buck20, digipot_wiper ) ) 
     { 
         buck_r1_kohm = BUCK20_RESISTOR_R6_KOHM +  
                        ( float ) ( BUCK20_DIGIPOT_MAX_KOHM * digipot_wiper ) / BUCK20_WIPER_FULL_SCALE; 
         buck_vout = BUCK20_BUCK_VREF + ( buck_r1_kohm * BUCK20_BUCK_VREF ) / BUCK20_BUCK_R2_KOHM; 
         log_printf( &logger, " Digipot wiper position: %urn", digipot_wiper ); 
         log_printf( &logger, " Approximate R1 (Digipot+R6): %.2f kOhmrn", buck_r1_kohm ); 
         log_printf( &logger, " Approximate buck voltage output: %.2f Vrnn", buck_vout ); 
         digipot_wiper += 50; 
         if ( digipot_wiper > BUCK20_WIPER_FULL_SCALE ) 
         { 
             digipot_wiper = BUCK20_WIPER_ZERO_SCALE; 
         } 
     } 
     Delay_ms ( 3000 ); 
 }

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

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.Buck20

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. A UART terminal is available in all Mikroe compilers.

mikroSDK

This Click board™ is supported with mikroSDK – Mikroe 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.