MIKROE-1592

      BUCK click PID: MIKROE-1592 BUCK click is a buck switching regulator that accepts a wide input voltage range of up to 40V and steps it down to 3.3V or 5V. The click carries the LT3976 40V, 5A, 2MHz step-down switching regulator with 3.3µA quiescent current. BUCK click communicates with the target microcontroller over the following pins on the mikroBUS™ line: PWM, INT, RS, CS. Note: When all the usual conditions and proper cooling are met BUCK click can supply up to 5A of load  current.  LT3976 regulator features The LT3976 is an adjustable frequency monolithic buck switching regulator that accepts a wide input voltage range up to 40V. Low quiescent current design consumes only 3.3µA of supply current while regulating with no load. Low ripple Burst Mode operation maintains high efficiency at low output currents while keeping the output ripple below 15mV in a typical application. The LT3976 can supply up to 5A of load current and has current limit foldback to limit power dissipation during short-circuit. A low dropout voltage of 500mV is maintained when the input voltage drops below the programmed output voltage, such as during automotive cold crank. How the click works There are two onboard screw terminals, one for connecting the external input supply, and the other for the output. There is also a multiplexer which chooses the resistor used for setting the switching frequency. The multiplexer is used for selecting one of the four different resistors. Each of these resistors, if selected, sets different switching frequency: A0  A1  Selects resistor  Switching frequency [MHz]  0  0  R7 = 130k  0.4  0  1  R8 = 32.4k  1.2  1  0  R9 = 54.9k  0.8  1  1  R10 = 21.5k  1.6  Specifications Type  Buck  Applications  Automotive battery regulation, portable devices, industrial supplies, etc.  On‐board  modules  LT3976 step‐down switching regulator, MAX4634 4‐channel CMOS analog multiplexer Key Features  Thermal shutdown protection, output voltage can be set to 3.3V or 5V, 4 possible  switching frequencies  Interface  GPIO  Input Voltage  3.3V or 5V  Click board size  L (57.15 x 25.4 mm)  Pinout diagram This table shows how the pinout on BUCK click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns). Notes  Pin  Pin  Notes    NC  1  AN  Multiplexer A0 pin   A0  2  RST  INT  Enable IC  EN  3  CS  NC  NC  PWM 16  A1  Multiplexer A1 pin   15  PG  Open drain output of an  internal comparator  TX  14  NC  4  SCK  RX  13  NC  5  MIS SCL  O  12  NC        NC  6      MOS SDA  11  I  NC  +5V  Power supply  GND  Ground  Power supply  +3.3V  7  3.3V  5V  Ground  GND  GND  GND  9  8  10     Jumpers and settings   Designator  Name  Default  Position  JP1  VOUT  SEL  JP2  VCC SEL  Left  Right  Default  Option  Description  3V3  Output Voltage Selection 3V3/5V, left position 5V, right  position 3V3.  3V3  Power Supply Voltage Selection toward host MCU  3V3/5V; left position 3V3, right position 5V  Programming Code examples for BUCK click, written for MikroElektronika hardware and compilers are available on Libstock. Code snippet This code enables the buck regulator and detects if the voltage is within 8.4% of final regulation voltage. 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 void systemInit() { UART1_Init(9600); } void Buck_Init() { GPIO_Digital_Output( GPIO_Digital_Output( GPIO_Digital_Output( GPIO_Digital_Input ( BUCK_ENABLE_PIN = 1; MUX_A0_PIN = 0; MUX_A1_PIN = 0; } void Buck_Task() { if (PG_PIN == 1) { &GPIOC_BASE, &GPIOD_BASE, &GPIOA_BASE, &GPIOD_BASE, _GPIO_PINMASK_2 ); _GPIO_PINMASK_13 ); _GPIO_PINMASK_0 ); _GPIO_PINMASK_10 ); 21 UART1_Write_text("Vout is within the final 8.4% of final regulation voltage"); 22 UART1_Write_Text( "rn" ); 23 delay_ms(1000); 24 } 25 26 } 27 28 void main() 29 { 30 systemInit(); 31 Buck_Init(); 32 33 while( 1 ) 34 { 35 Buck_Task(); 36 } 37 }                                                                         https://shop.mikroe.com/buck‐click 9‐6‐17