PWM driver click

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PWM driver click
Pwm-driver-click-front-shop-crop.jpg
PWM driver click
IC/Module Si8711CC datasheet
Interface PWM
Power supply 5V
Product page www.mikroe.com/click/pwm-driver
Schematic PWM driver click schematic

If you need to control DC motors with loads up to 10A, PWM driver click is the perfect solution, thanks to the Silicon Lab Si8711CC one-channel isolator. It communicates with the target MCU over PWM pin, and runs on a 5V power supply. It can be used in a wide variety of ways, from controlling light intensity to serving as an ON/OFF switch to control DC load circuits.

Features and usage notes

MOSFET transistor

The click contains a P-channel DMP3010LK3 MOSFET transistor. When the click is used for PWM control it is not recommended to use it with loads of wattage over 50W because the MOSFET chip can get overheated. However, this does not apply when the click is used as an ON/OFF switch.

Onboard screw terminals

There are two pairs of screw terminals on the PWM driver click — one for the external power supply and one for the DC load.

Key features

  • Si8711CC isolator from Silicon Labs
    • Data rates dc to 15 Mbps
    • 1 channel diode emulator input
  • PWM pin interface
  • Two pairs of screw terminals
  • 5V power supply

Pinout diagram

This table shows how the pinout on PWM driver click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes Pin Mikrobus logo.png

mikroBUStm

Pin Notes
NC 1 AN X PWM 16 PWM PWM or GPIO (ON/OFF) when used as a switch
NC 2 RST INT 15 NC
NC 3 CS TX 14 NC
NC 4 SCK RX 13 NC
NC 5 MISO SCL 12 NC
NC 6 MOSI SDA 11 NC
This click runs on 5V power supply only NC 7 +3.3V +5V 10 +5V Power supply
Ground GND 8 GND GND 9 GND Ground

Additional information about the click

There are two pairs of screw terminals on the PWM click. The table below shows their function.

Designator Name Type (LED, BUTTON…) Description
LD1 PWR LED Power LED
CN1 EXTPWR CONNECTOR External power supply connection
CN2 LOAD CONNECTOR Load connection

Programming

This demo demonstrates the change of light intensity of a halogen lamp; using the on-board potentiometer P1 (EasyPIC 7), you can regulate the light intensity. For this demo we have used the EasyPIC v7 development system.

  • Supply voltage within range of 3 – 30 V.
  • Maximum output current detected: 15 mA.
  • Wide operating temperature range: –40 to +125 °C
  • Demo available for: ARM, PIC, PIC32, AVR and FTDI compilers.

This snippet shows the initialization of MCU (PWM and required port pins)  and LCD. In an endless loop, we are reading current digitized value from ADC channel 1 and showing it's value with light intensity. Also, luminosity percentage is given on the LCD. 

 1 void main()
 2   {
 3     MCU_Init();                         // Configure PORTB pins as digital
 4     Lcd_Init();                         // Initialize Lcd
 5     Lcd_Display();                      // Display text
 6     current_duty  = 0;
 7     PWM2_Start();
 8     PWM2_Set_Duty(current_duty);
 9 
10     while ( 1 )                         // Playing with Potentiometer P1 you can control current PWM duty cycle
11                                         // For visual result, look at LED PC1
12     {
13       uint8_t cur_duty_byte;
14 
15       // Read 10 - bit ADC value and set newly acquired 8 - bit PWM duty
16       adc_rd = ADC_Read(1) & 0x0000FFFF;
17       current_duty = adc_rd / 4 ;
18       cur_duty_byte = LoWord(current_duty);
19       PWM2_Set_Duty(cur_duty_byte);          // Set newly acquired duty
20       cur_duty_byte = cur_duty_byte * 0.39;  // 100 / 256
21       ByteToStr(cur_duty_byte, txt);
22       Lcd_Out(2, 11, txt);
23       Delay_ms( 20 );
24     }
25   }

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